Evidence Technician Certification (ETC) — Questions and Answers

Question 1: What is the purpose of a control sample in forensic laboratory analysis?

To replace the original evidence during testing
To establish a baseline for comparison and validate test results (Correct answer)
To store evidence in a refrigerated environment
To document the chain of custody of the sample

Correct answer: To establish a baseline for comparison and validate test results

A control sample provides a known baseline so analysts can confirm the test is performing correctly and results are valid.

Question 2: Why should biological evidence never be packaged in sealed plastic bags for long-term storage?

Moisture trapped inside promotes bacterial growth and mold that degrades DNA (Correct answer)
UV light penetrates plastic and degrades the sample
Plastic generates static electricity that damages DNA
Plastic bags are not tamper-evident enough for evidence storage

Correct answer: Moisture trapped inside promotes bacterial growth and mold that degrades DNA

Sealed plastic traps moisture, creating an environment where bacteria and mold thrive, rapidly degrading biological evidence and the DNA within it.

Question 3: An evidence technician seizes a laptop that is encrypted with BitLocker. What should be done to preserve potential access?

Immediately power it off and submit to the lab
Force-boot from a USB drive to bypass encryption
Keep it powered on if possible, document any visible passwords/recovery keys, and transport it safely to avoid sleep mode (Correct answer)
Contact the manufacturer to unlock it remotely

Correct answer: Keep it powered on if possible, document any visible passwords/recovery keys, and transport it safely to avoid sleep mode

Keeping the encrypted laptop powered on may preserve the decryption key in RAM, and recovery keys displayed or written nearby may be needed to access the drive later.

Question 4: What are the three fundamental fingerprint pattern types recognized in classification systems?

Loops, whorls, and arches (Correct answer)
Radial loops, ulnar loops, and composites
Ridges, valleys, and deltas
Tented arches, plain whorls, and accidentals

Correct answer: Loops, whorls, and arches

All fingerprint patterns are classified into three fundamental types: loops (most common), whorls, and arches.

Question 5: When should an evidence technician collect reference standards from a victim?

Only when specifically ordered by a prosecutor
As early as possible during the investigation (Correct answer)
Only after the suspect is identified
After all other scene evidence is collected

Correct answer: As early as possible during the investigation

Reference standards from victims should be collected as early as possible to preserve sample integrity and enable comparison analysis.

Question 6: A firearm is found submerged in water. How should it be transported to the lab?

Submitted submerged in the water in which it was found (Correct answer)
Air-dried on scene and then placed in a cardboard box
Drained and sealed in a plastic bag with desiccant
Removed, dried immediately, then packaged in paper

Correct answer: Submitted submerged in the water in which it was found

Firearms recovered from water should be transported submerged to preserve potential DNA and fingerprints that would be destroyed by drying.

Question 7: When collecting soil samples as potential evidence, a technician should collect comparison samples from:

Adjacent areas surrounding the evidence location as well as a control sample from an unrelated area (Correct answer)
The nearest public roadway
Multiple areas at least 20 feet away from the evidence
Only the exact location where evidence was found

Correct answer: Adjacent areas surrounding the evidence location as well as a control sample from an unrelated area

Comparison soil samples should be taken from the immediate surrounding area and a separate control location to allow forensic comparison.

Question 8: An evidence technician submits a white powder to the lab. Which presumptive test would indicate the possible presence of cocaine?

Mecke reagent test
Scott test (cobalt thiocyanate) (Correct answer)
Duquenois-Levine test
Marquis reagent test

Correct answer: Scott test (cobalt thiocyanate)

The Scott test produces a blue color in the presence of cocaine, serving as a presumptive indicator before confirmatory analysis.

Question 9: What is gunshot residue (GSR) primarily composed of, and why is it significant as trace evidence?

Carbon and nitrogen compounds indicating smokeless powder
Lead, barium, and antimony particles unique to firearm discharge (Correct answer)
Iron oxide and copper from the bullet jacket only
Nitrates and nitrites from the propellant gases

Correct answer: Lead, barium, and antimony particles unique to firearm discharge

The unique tri-element combination of lead, barium, and antimony in fused spherical particles is characteristic of primer discharge and is detectable on hands, clothing, and surfaces near a fired weapon.

Question 10: Which type of evidence packaging is most appropriate for wet biological samples?

Aluminum foil wrapping
Airtight plastic bags sealed immediately
Paper bags or breathable containers to prevent mold growth (Correct answer)
Standard zip-lock plastic bags

Correct answer: Paper bags or breathable containers to prevent mold growth

Wet biological samples should be placed in breathable paper bags or containers to allow moisture to escape and prevent mold, which would degrade the evidence.

Question 11: Which fingerprint development technique is most appropriate for latent prints on wet evidence?

Ninhydrin
Cyanoacrylate fuming
Small particle reagent (SPR) (Correct answer)
Standard carbon powder

Correct answer: Small particle reagent (SPR)

Small particle reagent (SPR) is a suspension of molybdenum disulfide that adheres to fatty components of latent prints even on wet surfaces.

Question 12: What is a minutiae point in fingerprint analysis?

A specific ridge characteristic such as a ridge ending or bifurcation used for comparison (Correct answer)
A smudge or distortion that obscures ridge detail
The center point of a fingerprint whorl
The overall pattern classification of a fingerprint

Correct answer: A specific ridge characteristic such as a ridge ending or bifurcation used for comparison

Minutiae are individual ridge features—primarily ridge endings and bifurcations—that are used as the basis for fingerprint comparison and identification.

Question 13: Which type of digital evidence storage media requires special anti-static precautions during collection and transport?

Memory cards used in cameras
USB flash drives only
Optical discs (CDs/DVDs) only
Hard drives, SSDs, and RAM modules are susceptible to electrostatic discharge (ESD) damage (Correct answer)

Correct answer: Hard drives, SSDs, and RAM modules are susceptible to electrostatic discharge (ESD) damage

Electronic storage media components are sensitive to electrostatic discharge, which can corrupt or destroy data; anti-static bags must be used during collection and transport.

Question 14: A defense attorney challenges the chain of custody for a DNA sample. What is the most important factor in sustaining its admissibility?

Whether the suspect confessed to the crime
The reputation of the lab that tested it
The cost of the DNA analysis
Complete, unbroken documentation of every person who handled the sample (Correct answer)

Correct answer: Complete, unbroken documentation of every person who handled the sample

Admissibility hinges on complete, unbroken documentation showing every individual who handled the DNA sample and under what circumstances.

Question 15: Which protocol governs the destruction or disposal of biological evidence after a case is adjudicated?

The technician's personal judgment
Federal EPA guidelines only
Applicable jurisdiction's evidence retention policy and court approval (Correct answer)
A 30-day automatic destruction rule

Correct answer: Applicable jurisdiction's evidence retention policy and court approval

Evidence destruction requires adherence to the jurisdiction's retention policy and, in many cases, court authorization, especially in serious felony cases where post-conviction review is possible.

Question 16: What physical property of glass fragments is measured to help determine whether two samples share a common origin?

Tensile strength
Surface hardness (Mohs scale)
Thermal conductivity
Refractive index (Correct answer)

Correct answer: Refractive index

Refractive index measures how much light bends when passing through glass and is highly consistent within a single production batch, making it a key comparison value.

Question 17: What documentation is required when seizing digital devices as evidence?

Only a property receipt with the device description
Photographs of the device, its connections, and screen; a complete inventory of all seized items with make, model, and serial number (Correct answer)
A written summary of the suspect's statements about the device
Video of the seizure and a signed consent form only

Correct answer: Photographs of the device, its connections, and screen; a complete inventory of all seized items with make, model, and serial number

Proper digital device seizure requires photographs showing the device's state and connections, plus a detailed inventory capturing make, model, serial number, and any visible damage.

Question 18: An evidence technician finds a spent cartridge casing at an outdoor shooting scene. The FIRST action should be to:

Pick it up and mark it immediately
Mark its location with a flag and move on to collect other items
Swab it for DNA before photographing
Photograph it in place with a scale marker before moving it (Correct answer)

Correct answer: Photograph it in place with a scale marker before moving it

All evidence must be photographed in its original position with a scale marker before collection to document the scene accurately.

Question 19: What type of fingerprint is formed when a finger presses into a soft material such as wax or putty, leaving a three-dimensional impression?

Patent print
Inked print
Plastic (impression) print (Correct answer)
Latent print

Correct answer: Plastic (impression) print

Plastic prints are three-dimensional impressions left in pliable materials like wax, putty, or fresh paint that retain the ridge detail in a molded form.

Question 20: What is the purpose of the Combined DNA Index System (CODIS)?

A federal standard for packaging biological evidence
A court database that stores trial evidence for appeals
A national database that stores DNA profiles to link crime scene evidence to known offenders or unsolved cases (Correct answer)
A laboratory instrument used to sequence DNA samples

Correct answer: A national database that stores DNA profiles to link crime scene evidence to known offenders or unsolved cases

CODIS is the FBI-managed national DNA database that contains profiles from convicted offenders, arrestees, and forensic unknowns, enabling matches between crime scenes and known individuals.

Question 21: During the collection of drug evidence, why should each pill, capsule, or powdered substance be packaged separately?

To prevent cross-contamination between different substances (Correct answer)
To allow each item to be weighed independently by the lab
Because law requires a separate form per substance type
So the total count can be verified at each custody transfer

Correct answer: To prevent cross-contamination between different substances

Packaging drug items separately prevents mixing of substances, which could affect identification, weight calculations, and charge levels.

Question 22: Which microscopy technique is used to compare tool marks and bullet striations in forensic firearm analysis?

Phase contrast microscopy
Comparison microscopy (Correct answer)
Scanning electron microscopy
Darkfield microscopy

Correct answer: Comparison microscopy

A comparison microscope places two samples side-by-side in the same field of view, allowing direct visual comparison of tool marks or ballistic striations.

Question 23: Which principle forms the scientific foundation for trace evidence and states that every contact leaves a trace?

Daubert Standard
Bertillon Identification System
Locard's Exchange Principle (Correct answer)
Frye Standard

Correct answer: Locard's Exchange Principle

Locard's Exchange Principle holds that whenever two objects come into contact, material is transferred between them, forming the basis for all trace evidence analysis.

Question 24: Bloodstain pattern analysis (BPA) can help investigators determine which of the following?

The direction, speed, and origin of blood shed at the crime scene (Correct answer)
The approximate time of death based on drying patterns
The victim's medical history from antibody markers in blood
The blood type and DNA profile of the victim

Correct answer: The direction, speed, and origin of blood shed at the crime scene

BPA examines the size, shape, distribution, and directionality of bloodstains to reconstruct the events that produced them, including point of origin and movement.

Question 25: What does AFIS stand for and what is its primary function?

Automated File Indexing System — it catalogs crime scene photos
Advanced Forensic Intelligence System — it stores DNA profiles
Analog Fingerprint Imaging Software — it scans paper cards
Automated Fingerprint Identification System — it electronically searches fingerprint databases for matches (Correct answer)

Correct answer: Automated Fingerprint Identification System — it electronically searches fingerprint databases for matches

AFIS is an Automated Fingerprint Identification System that digitally encodes fingerprint minutiae and searches large databases to identify potential matches.

Question 26: When a chain of custody form is lost for a piece of evidence, what is the most appropriate course of action?

Document the loss, notify supervisors, and attempt reconstruction from available records (Correct answer)
Continue processing as if the form exists
Discard the evidence to avoid legal complications
Recreate the form from memory

Correct answer: Document the loss, notify supervisors, and attempt reconstruction from available records

Losing a chain of custody form requires immediate documentation of the loss, supervisor notification, and reconstruction from any available records to maintain evidentiary integrity.

Question 27: Which container is best for collecting wet biological evidence?

Glass jar
Metal box
Plastic bag
Paper bag (Correct answer)

Correct answer: Paper bag

Wet biological evidence, such as blood or tissue, should be collected in a breathable container like a paper bag. This allows the evidence to air dry naturally, preventing the growth of mold and bacteria that can degrade DNA and other biological material. Plastic bags or sealed containers trap moisture, which can lead to spoilage and compromise the evidence's integrity.

Question 28: Forensic DNA analysis uses STR (Short Tandem Repeat) profiling. How many STR loci does CODIS analyze?

10 core loci
15 core loci
20 core loci (Correct answer)
5 core loci

Correct answer: 20 core loci

The FBI's CODIS system was expanded in 2017 to include 20 core STR loci, significantly reducing the likelihood of a coincidental match.

Question 29: Which type of evidence requires storage in a humidity-controlled environment to prevent cracking or warping?

Synthetic fibers
Glass fragments
Wooden tool handles and document paper (Correct answer)
Metal shell casings

Correct answer: Wooden tool handles and document paper

Wood and paper are hygroscopic materials that expand, crack, or warp with humidity fluctuations, which can alter tool mark patterns and obliterate handwriting impressions.

Question 30: An evidence technician is preparing to purge old evidence from storage. What documentation must be completed before destruction?

A destruction authorization form signed by the appropriate authority, case disposition confirmation, and a destruction log entry (Correct answer)
A verbal confirmation from the detective
No documentation is necessary once the case is closed
Only a note in the evidence log

Correct answer: A destruction authorization form signed by the appropriate authority, case disposition confirmation, and a destruction log entry

Evidence destruction requires a signed authorization form from the appropriate authority, case disposition confirmation, and a destruction log entry to create a permanent record of what was destroyed and by whose authority.

Question 31: A sexual assault evidence kit (SAEK) is typically stored at what temperature prior to submission to the crime lab?

Room temperature (20–25°C)
Frozen (-20°C or below)
Refrigerated (2–8°C) (Correct answer)
Heated (37°C)

Correct answer: Refrigerated (2–8°C)

SAEKs containing biological swabs and samples are refrigerated at 2–8°C to slow degradation while preventing freeze-thaw damage to delicate biological materials.

Question 32: Which type of analysis uses ninhydrin reagent to develop latent fingerprints on porous surfaces such as paper?

Magnetic powder dusting
Amino acid-based chemical development (Correct answer)
Alternate light source illumination
Cyanoacrylate fuming

Correct answer: Amino acid-based chemical development

Ninhydrin reacts with amino acids left by skin oils to develop purple-colored latent prints on porous surfaces like paper.

Question 33: Why is tamper-evident packaging used?

To speed up transfers
To prevent and detect tampering (Correct answer)
To add color to bags
To simplify labeling

Correct answer: To prevent and detect tampering

Tamper-evident packaging is designed with features that clearly indicate if a container has been opened or altered after being sealed. This provides a visual safeguard against unauthorized access or manipulation of evidence, ensuring its integrity and admissibility in court. It demonstrates that the evidence has remained undisturbed since its collection.

Question 34: When submitting biological evidence to a forensic lab, which packaging material is preferred over plastic bags?

Aluminum foil wrapping
Vacuum-sealed plastic pouches
Sealed plastic zip-lock bags
Paper bags or paper envelopes (Correct answer)

Correct answer: Paper bags or paper envelopes

Paper packaging allows moisture to escape, preventing mold and bacterial growth that would degrade DNA and other biological evidence.

Question 35: Which analytical technique is most commonly used to determine the chemical composition and polymer type of fiber evidence?

Fourier transform infrared spectroscopy (FTIR) (Correct answer)
Atomic absorption spectroscopy
X-ray diffraction (XRD)
Gas chromatography alone

Correct answer: Fourier transform infrared spectroscopy (FTIR)

FTIR produces a unique infrared absorption spectrum that acts as a chemical fingerprint for fiber polymers, allowing examiners to identify and compare fiber types.

Question 36: Which documentation method provides the most accurate spatial data for reconstructing a crime scene?

Total station or 3D laser scanning (Correct answer)
Handheld GPS coordinates
Sketching with compass bearings only
Narrative report

Correct answer: Total station or 3D laser scanning

Total stations and 3D laser scanners capture precise x, y, z coordinates of all scene elements, enabling accurate reconstruction.

Question 37: When collecting fire debris from an arson scene for accelerant analysis, what type of container should be used?

Standard plastic zip-lock evidence bags
Airtight metal cans or heat-sealed nylon bags (Correct answer)
Paper evidence bags to allow gases to escape
Glass bottles with loosely capped lids

Correct answer: Airtight metal cans or heat-sealed nylon bags

Airtight metal cans or nylon bags trap volatile accelerant vapors that would otherwise evaporate, preserving them for headspace analysis and gas chromatography/mass spectrometry.

Question 38: An evidence technician receives a damaged hard drive with a failed read head. What is the appropriate action?

Open the drive casing to manually inspect the platters
Attempt to copy files using standard software before submitting
Freeze the drive to re-enable the read head temporarily
Submit it to a specialized digital forensics lab for clean-room data recovery without attempting to access it (Correct answer)

Correct answer: Submit it to a specialized digital forensics lab for clean-room data recovery without attempting to access it

A hard drive with a failed read head requires clean-room recovery by specialists; any attempt to run the drive further risks permanent platter damage and data loss.

Question 39: What is the chain of custody requirement when submitting lifted fingerprint cards to the laboratory?

The chain of custody only applies to physical objects, not lift cards
Lift cards are exempt from chain of custody because they are copies
Only the submitting officer needs to sign the lift card
Each person who handles the lift must sign and date, documenting the transfer to maintain an unbroken chain (Correct answer)

Correct answer: Each person who handles the lift must sign and date, documenting the transfer to maintain an unbroken chain

Fingerprint lift cards are evidence and must maintain an unbroken chain of custody with each handler signing and dating to document every transfer.

Question 40: What is the proper technique for collecting a dried bloodstain from a non-porous surface?

Apply luminol to rehydrate and collect with a cloth swab sealed in plastic
Moisten a sterile swab with distilled water, collect the stain, air dry the swab completely, and package in paper (Correct answer)
Use adhesive tape to lift the stain and place on a backing card
Scrape the stain into a plastic vial and seal immediately

Correct answer: Moisten a sterile swab with distilled water, collect the stain, air dry the swab completely, and package in paper

Dried bloodstains on non-porous surfaces should be collected with a moistened sterile swab, air-dried to prevent bacterial degradation, and packaged in breathable paper.

Question 41: What is the order of volatility in digital forensics, and why does it matter to evidence technicians?

Less volatile data should be collected first to ensure long-term preservation
Most volatile data (RAM, cache) must be collected first before less volatile data (hard drive, backups), as it is lost most quickly (Correct answer)
Only non-volatile data has evidentiary value in court
Volatility does not affect collection order; all data should be collected simultaneously

Correct answer: Most volatile data (RAM, cache) must be collected first before less volatile data (hard drive, backups), as it is lost most quickly

The order of volatility dictates that evidence technicians collect the most ephemeral data first (RAM, network state, running processes) before it is lost, followed by persistent storage.

Question 42: Evidence technicians may be asked to obtain inked fingerprints from a deceased person. Which technique is used when skin is wrinkled or decomposed?

Luminol enhancement on the body
Standard ink card rolling without modification
Casting with dental stone
Tissue builder injection or rehydration using softening solutions prior to inking (Correct answer)

Correct answer: Tissue builder injection or rehydration using softening solutions prior to inking

Wrinkled or decomposed skin is treated with tissue builder injections or rehydration solutions to restore skin elasticity before inking, enabling legible prints.

Question 43: What is the first step an evidence technician should take upon encountering a powered-on computer at a crime scene?

Immediately shut it down by pulling the power cord
Photograph the screen, document its state, and consult with a digital forensics specialist before touching it (Correct answer)
Restart the computer to capture a fresh state
Log into the system to check recent files

Correct answer: Photograph the screen, document its state, and consult with a digital forensics specialist before touching it

Documenting the screen's current state before any action preserves volatile data and allows a digital forensics specialist to advise on whether to acquire live data or power down.

Question 44: Which analytical technique is considered the gold standard for identifying and quantifying drugs in seized samples?

Gas chromatography-mass spectrometry (GC-MS) (Correct answer)
Thin-layer chromatography (TLC)
Infrared spectroscopy only
Colorimetric field testing

Correct answer: Gas chromatography-mass spectrometry (GC-MS)

GC-MS separates compounds by gas chromatography then identifies them by mass spectrometry, providing highly accurate drug identification.

Question 45: The 'Locard Exchange Principle' is most directly relevant to crime scene processing because it states that:

Every crime scene must be photographed before touching anything
Chain of custody must be maintained at all times
Evidence must be collected in order of fragility
When two objects contact each other, trace material is exchanged (Correct answer)

Correct answer: When two objects contact each other, trace material is exchanged

Locard's principle holds that every contact between a person and a scene results in the transfer of trace material in both directions.

Question 46: What does a 'confirmatory test' in forensic analysis provide that a presumptive test does not?

A rapid field screening result
A definitive, scientifically validated identification of the substance (Correct answer)
A color-change indicator for the presence of a substance
An approximate concentration estimate

Correct answer: A definitive, scientifically validated identification of the substance

Confirmatory tests use validated instrumental methods (e.g., GC-MS) to provide a definitive identification that is admissible as conclusive evidence in court.

Question 47: Before testifying, an evidence technician should review which documents to prepare for court?

The final verdict from a similar prior case
Their written reports, chain of custody forms, photographs, and any notes taken at the time of collection (Correct answer)
Only the prosecutor's summary of evidence
The defendant's criminal history and prior convictions

Correct answer: Their written reports, chain of custody forms, photographs, and any notes taken at the time of collection

Reviewing original reports, chain of custody records, photographs, and contemporaneous notes ensures the technician's testimony is accurate and consistent with documented findings.

Question 48: A technician must collect a control swab when swabbing a surface for biological evidence. The control swab should be taken from:

A swab moistened only with the same reagent used
A different surface material entirely
An unstained area of the same surface near the stain (Correct answer)
The center of the suspected stain

Correct answer: An unstained area of the same surface near the stain

The control swab is collected from an unstained area of the same surface to detect background contamination from the substrate itself.

Question 49: Which powder is preferred for developing latent prints on dark, non-porous surfaces?

Magnetic powder for rough surfaces
Black powder (e.g., carbon or graphite)
White or light-colored powder (e.g., titanium dioxide) (Correct answer)
Fluorescent powder under alternate light source

Correct answer: White or light-colored powder (e.g., titanium dioxide)

Light-colored powders provide the necessary contrast to visualize latent prints on dark non-porous surfaces.

Question 50: When must an evidence technician stop collecting evidence at a scene and request additional authorization?

When a supervisor is not immediately present
When more than 50 items have already been collected
When the collection takes longer than the estimated time
When evidence is discovered in an area not covered by the current search warrant (Correct answer)

Correct answer: When evidence is discovered in an area not covered by the current search warrant

Collecting evidence beyond the scope of the current search warrant is a Fourth Amendment violation; a new or amended warrant must be obtained before continuing.

Question 51: Which standard is most commonly referenced when establishing evidence documentation protocols in U.S. law enforcement agencies?

FBI psychological profiling standards
SWGMAT (Scientific Working Group for Materials Analysis) guidelines and ANSI/ASB standards (Correct answer)
OSHA hazard communication standards
ISO 9001

Correct answer: SWGMAT (Scientific Working Group for Materials Analysis) guidelines and ANSI/ASB standards

SWGMAT guidelines and ANSI/ASB standards provide the scientific and procedural benchmarks most commonly referenced for evidence documentation in U.S. law enforcement.

Question 52: What role does sketching play in crime scene processing?

Decorates the report
Acts as the final report
Supports spatial understanding and measurements (Correct answer)
Replaces photographs

Correct answer: Supports spatial understanding and measurements

Crime scene sketches provide a visual representation of the scene, showing the relative positions of evidence and fixed objects. They include accurate measurements and distances, which are crucial for reconstructing the scene and understanding spatial relationships that photographs alone cannot fully convey. Sketches complement photographs by adding a measurable, scaled perspective, aiding in detailed analysis and court presentations.

Question 53: What is a best practice for preserving digital evidence?

Label only with a color code
Use write-protected media and restrict access (Correct answer)
Convert to paper form
Store on flash drives without protection

Correct answer: Use write-protected media and restrict access

Preserving digital evidence requires safeguarding it from alteration or corruption. Using write-protected media ensures that the original data cannot be accidentally or intentionally changed. Restricting access to authorized personnel further prevents tampering and maintains the integrity and admissibility of the digital evidence in court.

Question 54: What is Locard's principle as it specifically applies to biological transfer evidence?

All biological samples degrade at the same rate in storage
When two individuals have contact, biological material such as hair, skin cells, and blood is exchanged between them (Correct answer)
Biological evidence must be tested within 72 hours of collection
DNA collected from a scene is always the perpetrator's

Correct answer: When two individuals have contact, biological material such as hair, skin cells, and blood is exchanged between them

Locard's Exchange Principle in biological evidence means that physical contact results in transfer of biological material like DNA, hair, and skin cells between persons and objects.

Question 55: Why must forensic analysts wear PPE including gloves and masks when handling evidence?

To comply with OSHA fire safety regulations only
To maintain a sterile environment for chemical synthesis
To prevent cross-contamination of the evidence with analyst DNA or materials (Correct answer)
To protect against radioactive evidence exclusively

Correct answer: To prevent cross-contamination of the evidence with analyst DNA or materials

PPE prevents the analyst's DNA, fingerprints, or other materials from contaminating evidence, which could invalidate results or compromise a prosecution.

Question 56: What is the difference between nuclear DNA and mitochondrial DNA in forensic evidence applications?

Mitochondrial DNA provides individual identification; nuclear DNA only shows family lineage
Nuclear DNA provides individual identification; mitochondrial DNA provides maternal lineage but is not individually unique (Correct answer)
Both types provide the same level of individual identification in forensic analysis
Nuclear DNA is found only in blood; mitochondrial DNA is found only in hair

Correct answer: Nuclear DNA provides individual identification; mitochondrial DNA provides maternal lineage but is not individually unique

Nuclear DNA contains unique individual genetic information, while mitochondrial DNA is inherited maternally and shared among maternal relatives, providing lineage but not individual identification.

Question 57: What is the delta in a fingerprint pattern?

A triangular ridge formation that marks a divergence of ridges, used as a reference point in classification (Correct answer)
The outer perimeter ridge line
The central core of a whorl pattern
A bifurcation minutiae point

Correct answer: A triangular ridge formation that marks a divergence of ridges, used as a reference point in classification

A delta is a triangular area where ridges diverge, serving as a key reference point for fingerprint classification; loops have one delta and whorls have two.

Question 58: What information should be recorded when evidence is returned from the crime lab to the evidence room?

Date, time, lab technician name, condition upon return, and receiving technician's signature (Correct answer)
The test results only
The name of the detective assigned to the case
Only the lab technician's name

Correct answer: Date, time, lab technician name, condition upon return, and receiving technician's signature

Upon return from the lab, the date, time, lab technician's name, the condition of the evidence, and the receiving technician's signature must all be recorded to maintain an unbroken chain.

Question 59: What is the primary purpose of photographing evidence before collection?

To document the original position and condition of evidence in context (Correct answer)
To replace written documentation entirely
To create a public record for news media
To satisfy insurance requirements

Correct answer: To document the original position and condition of evidence in context

Photographing evidence before collection captures its original position and condition within the scene context, which written notes alone cannot fully convey.

Question 60: Why is it important to place a cell phone in a Faraday bag or airplane mode immediately upon seizure?

To avoid static electricity damage during transport
To charge the battery before lab analysis
To trigger the phone's backup feature
To prevent remote wiping, incoming data, or location updates that could alter evidence (Correct answer)

Correct answer: To prevent remote wiping, incoming data, or location updates that could alter evidence

Isolating the phone from wireless signals prevents remote wipe commands, new incoming messages, or GPS updates from altering the data on the device.

Question 61: When documenting the seizure of a network router as digital evidence, what information should be photographed before disconnecting it?

The power adapter and cable only
Only the front of the device for identification purposes
All status indicator lights, cable connections and labeled ports, and any visible configuration information (Correct answer)
The router's default password label on the bottom

Correct answer: All status indicator lights, cable connections and labeled ports, and any visible configuration information

Photographing the router's indicator lights, labeled cable connections, and configuration data preserves the network state and documents how devices were connected before seizure.

Question 62: How many points of comparison are required by US federal standards to declare a fingerprint identification?

There is no mandated minimum — examiners use a holistic sufficiency standard (Correct answer)
A minimum of 12 points is federally mandated
A minimum of 8 points is federally mandated
A minimum of 16 points is federally mandated

Correct answer: There is no mandated minimum — examiners use a holistic sufficiency standard

The FBI and most US agencies follow a sufficiency standard rather than a fixed point minimum; the examiner must find sufficient unique features without unexplained differences.

Question 63: Cyanoacrylate (superglue) fuming is primarily used to develop latent prints on which type of surface?

Fabric and clothing materials
Porous surfaces such as paper and cardboard
Non-porous surfaces such as plastic, glass, and metal (Correct answer)
Rough concrete or brick surfaces

Correct answer: Non-porous surfaces such as plastic, glass, and metal

Cyanoacrylate fuming causes superglue vapors to polymerize on the amino acids, fatty acids, and proteins in latent print residue on non-porous surfaces.

Question 64: Which chemical method uses the ninhydrin reaction to develop latent prints on paper documents in a dry environment?

Rhodamine 6G under alternate light source
Superglue fuming in a sealed chamber
Sudan black immersion bath
Ninhydrin dip or spray followed by gentle heat application (Correct answer)

Correct answer: Ninhydrin dip or spray followed by gentle heat application

Ninhydrin is applied by dipping or spraying on porous surfaces, then gently heated to accelerate the reaction with amino acids, producing a purple (Ruhemann's purple) color.

Question 65: What is the exclusionary rule and how does it affect improperly collected evidence?

Hearsay evidence is excluded unless it meets a recognized exception
Evidence collected more than 30 days after the crime is excluded as stale
Evidence obtained in violation of the Fourth Amendment must be excluded from trial to deter unlawful police conduct (Correct answer)
Evidence that is contaminated in the lab must be excluded as unreliable

Correct answer: Evidence obtained in violation of the Fourth Amendment must be excluded from trial to deter unlawful police conduct

The exclusionary rule (from Mapp v. Ohio) prohibits the use of evidence obtained through unconstitutional searches and seizures, deterring Fourth Amendment violations.

Question 66: When collecting a buccal swab (DNA reference sample) from a suspect, which area of the mouth is swabbed?

The tongue surface for maximum cell yield
The gums adjacent to the front teeth only
The inner cheek (buccal mucosa) using a firm rotational swabbing motion (Correct answer)
The roof of the mouth (palate)

Correct answer: The inner cheek (buccal mucosa) using a firm rotational swabbing motion

Buccal swabs collect epithelial cells from the inner cheek (buccal mucosa), providing a clean reference DNA sample; multiple swabs from both cheeks may be collected.

Question 67: When packaging sharp objects such as knives or broken glass as evidence, what is the priority safety concern?

Preventing rust or oxidation of the metal
Maintaining the sterile field around the cutting edge
Avoiding contact with any biological material
Protecting personnel from injury during handling and transport (Correct answer)

Correct answer: Protecting personnel from injury during handling and transport

Sharp objects must be packaged to prevent punctures during handling and transport, protecting evidence technicians, officers, and laboratory personnel.

Question 68: When collecting hair evidence, what is the minimum number of hairs typically required for comparison purposes?

At least 15–25 representative hairs from multiple areas of the scalp for reference samples (Correct answer)
Three to five hairs from any one location
Hair cannot be used for comparison — only DNA extraction
A single hair is sufficient for all comparisons

Correct answer: At least 15–25 representative hairs from multiple areas of the scalp for reference samples

Reference hair samples require 15–25 representative hairs from multiple scalp regions to capture the natural variation in hair characteristics for comparison.

Question 69: A technician collects multiple pieces of evidence from the same scene. What is the correct packaging practice?

Package all items together to maintain scene context
Package each item separately with individual labeling (Correct answer)
Package items in order of their collection priority
Package items by category (biological, trace, physical)

Correct answer: Package each item separately with individual labeling

Each piece of evidence must be individually packaged and labeled to prevent cross-contamination and maintain distinct chain of custody.

Question 70: What is the significance of the term 'continuous chain of custody' in evidence management?

Evidence is never moved once it enters the evidence room
The same officer handles the evidence from collection to court
Evidence is monitored 24 hours a day by security cameras
Every transfer and handling of evidence is documented without any unaccounted gaps from collection to final disposition (Correct answer)

Correct answer: Every transfer and handling of evidence is documented without any unaccounted gaps from collection to final disposition

A continuous chain of custody means every handling, transfer, and location of evidence is documented without gaps, ensuring no unauthorized access or alteration could have occurred.

Question 71: What does a positive result from a phenolphthalein (Kastle-Meyer) test indicate?

Confirmed presence of semen
Presence of cocaine alkaloids
Presence of cannabis resin
Presumptive presence of blood (hemoglobin catalyzes the reaction to produce pink color) (Correct answer)

Correct answer: Presumptive presence of blood (hemoglobin catalyzes the reaction to produce pink color)

The Kastle-Meyer test uses phenolphthalein; hemoglobin acts as a catalyst causing the reagent to turn pink, indicating a presumptive positive for blood.

Question 72: Which type of forensic analysis examines the unique characteristics of handwriting to compare questioned documents?

Questioned document examination (QDE) (Correct answer)
Latent print analysis
Trace evidence analysis
Ballistic fingerprinting

Correct answer: Questioned document examination (QDE)

Questioned document examination analyzes handwriting, typefaces, ink, and paper characteristics to determine authenticity or authorship.

Question 73: Which of the following is NOT a valid method for collecting DNA evidence from a suspect's skin?

Hair sample pulled from root
Rubbing a cotton swab over the back of the hand (Correct answer)
Blood draw with consent or court order
Buccal (cheek) swab

Correct answer: Rubbing a cotton swab over the back of the hand

A dry cotton swab rubbed over intact skin rarely collects enough epithelial cells for a reliable DNA profile, making it an unreliable collection method.

Question 74: When an evidence technician testifies in court, what is the primary purpose of their testimony?

To advocate for the prosecution's theory of the case
To present factual observations and technical findings objectively without offering opinions beyond their expertise (Correct answer)
To explain the defendant's motive based on evidence collected
To summarize witness statements gathered during the investigation

Correct answer: To present factual observations and technical findings objectively without offering opinions beyond their expertise

An evidence technician testifies as a fact witness or limited expert, presenting objective observations and technical findings relevant to how evidence was collected and processed.

Question 75: At a crime scene, a technician finds a partial latent fingerprint on a drinking glass. What is the correct collection sequence?

Photograph the print, then lift it or collect the entire object (Correct answer)
Dust the print, lift it, and discard the glass
Submit only a photograph of the print as evidence
Collect the glass immediately without further processing

Correct answer: Photograph the print, then lift it or collect the entire object

The print must first be documented photographically before any physical collection attempt, preserving the original state of the evidence.

Question 76: A technician is processing a vehicle involved in a hit-and-run. Which surface is MOST likely to yield transfer paint evidence?

The contact point of impact on the vehicle's exterior (Correct answer)
The interior door panels
The engine compartment
The undercarriage

Correct answer: The contact point of impact on the vehicle's exterior

The point of impact is where paint transfer between vehicles occurs, making it the primary location for collecting paint chip or smear evidence.

Question 77: What is voir dire in the context of an expert witness qualification?

A preliminary questioning by the court and attorneys to determine whether a witness qualifies as an expert (Correct answer)
The reading of Miranda rights to a suspect
A French legal term for presenting closing arguments
The process of swearing in a witness before testimony

Correct answer: A preliminary questioning by the court and attorneys to determine whether a witness qualifies as an expert

Voir dire in expert witness qualification is a preliminary examination where both sides question a proposed expert to determine if they possess the necessary specialized knowledge to offer opinions.

Question 78: A technician discovers latent prints on a firearm. What is the recommended sequence before processing?

Render safe, process for prints, then photograph
Photograph, swab for DNA, process for prints, then render safe
Photograph, render safe, process for prints, then swab for DNA
Render safe, photograph, swab for DNA, then process for prints (Correct answer)

Correct answer: Render safe, photograph, swab for DNA, then process for prints

Firearms must be rendered safe first for officer safety, then documented, with DNA swabbing done before print processing to avoid cross-contamination.

Question 79: Which practice helps prevent cross-contamination when packaging multiple items from the same crime scene?

Documenting items but not packaging them separately
Packaging each item separately in its own labeled container (Correct answer)
Packaging all items together in one large bag for efficiency
Wearing the same gloves throughout the entire collection process

Correct answer: Packaging each item separately in its own labeled container

Each item must be individually packaged to prevent cross-contamination, which could compromise DNA or trace evidence analysis and complicate the chain of custody.

Question 80: What type of bloodstain results from blood dripping into existing blood at a lower velocity?

Transfer pattern from contact with a wet blood source
Satellite spatter pattern with secondary droplets around the primary stain (Correct answer)
Cast-off pattern in an arc
Impact spatter from a blow

Correct answer: Satellite spatter pattern with secondary droplets around the primary stain

When blood drips into pooled blood, secondary satellite droplets are produced around the primary stain, indicating blood dripping at low velocity onto a wet surface.

Question 81: What is luminescence testing used for in biological evidence processing?

To sterilize biological samples before laboratory analysis
To detect latent bloodstains or other biological fluids that are not visible to the naked eye (Correct answer)
To photograph fluorescent trace evidence under white light
To permanently label evidence packaging with UV ink

Correct answer: To detect latent bloodstains or other biological fluids that are not visible to the naked eye

Alternate light sources and luminescent reagents like luminol reveal blood and other biological fluids that have been cleaned or diluted, making invisible stains visible for collection.

Question 82: Which hashing algorithm is most commonly used to verify the integrity of a digital evidence image?

CRC32 only
MD5 or SHA-256 (Correct answer)
Base64 encoding
AES-256 encryption

Correct answer: MD5 or SHA-256

MD5 and SHA-256 cryptographic hash values are computed before and after imaging; matching hashes confirm the copy is identical to the original.

Question 83: What is the role of a forensic laboratory's evidence custodian?

To collect evidence directly from crime scenes
To testify as an expert witness in court
To maintain chain of custody records and control access to submitted evidence (Correct answer)
To perform chemical analysis on submitted samples

Correct answer: To maintain chain of custody records and control access to submitted evidence

The lab evidence custodian is responsible for receiving, logging, storing, and tracking all submitted evidence to maintain an unbroken chain of custody.

Question 84: When photographing a developed latent fingerprint, what must always be included in the frame?

A scale ruler placed adjacent to the print (Correct answer)
The evidence technician's badge number
A color calibration chart only
The full crime scene in the background

Correct answer: A scale ruler placed adjacent to the print

A scale ruler (scale bar) must be photographed adjacent to the print so that images can be enlarged to 1:1 scale for accurate comparison.

Question 85: What professional obligation does an evidence technician have if their analysis produces results that are exculpatory (favorable to the defendant)?

Evidence technicians are not responsible for legal interpretations of their findings
They should only report findings that support the prosecution's case
They must report all findings truthfully regardless of which party they benefit, as Brady v. Maryland requires disclosure of exculpatory evidence (Correct answer)
Exculpatory results should be communicated only to the defense attorney directly

Correct answer: They must report all findings truthfully regardless of which party they benefit, as Brady v. Maryland requires disclosure of exculpatory evidence

Brady v. Maryland mandates that all exculpatory evidence be disclosed; evidence technicians must report all factual findings truthfully, as suppressing exculpatory results violates defendants' constitutional rights.

Question 86: Why is it important to use a systematic search method?

To allow random movement
To avoid missing evidence (Correct answer)
To reduce manpower needs
To speed up documentation

Correct answer: To avoid missing evidence

Using a systematic search method, such as grid, spiral, or strip search, ensures that every area of the crime scene is thoroughly examined. This methodical approach minimizes the chance of overlooking crucial evidence, which might otherwise be missed during a haphazard or unorganized search. It provides comprehensive coverage and improves the likelihood of discovering all relevant items.

Question 87: What is the primary difference between a patent print and a latent print?

A patent print is three-dimensional; a latent print is two-dimensional
A patent print is from a toe; a latent print is from a finger
A patent print is left on paper; a latent print is left on glass
A patent print is visible to the naked eye; a latent print requires development to be seen (Correct answer)

Correct answer: A patent print is visible to the naked eye; a latent print requires development to be seen

Patent prints are visible without enhancement (e.g., prints in blood or grease), while latent prints are invisible and require development techniques to visualize.

Question 88: When lifting a developed latent fingerprint with tape, what should be done immediately after lifting?

Submit the tape directly to the lab without further processing
Photograph the tape under UV light before backing it
Apply a second layer of tape for protection
Place the tape on a contrasting backing card and label with case information (Correct answer)

Correct answer: Place the tape on a contrasting backing card and label with case information

After lifting with tape, the print must be immediately placed on a contrasting backing card to preserve ridge detail and labeled with case, date, and location information.

Question 89: Paint transfer evidence from a hit-and-run scene is best characterized using which combination of analytical methods?

UV-Vis spectrophotometry alone
Standard optical microscopy only
FTIR spectroscopy and scanning electron microscopy with EDX (SEM-EDX) (Correct answer)
Visual comparison and simple chemical tests

Correct answer: FTIR spectroscopy and scanning electron microscopy with EDX (SEM-EDX)

FTIR identifies the organic binder and pigment chemistry of paint layers, while SEM-EDX provides elemental composition of inorganic pigments, together allowing detailed layer-by-layer comparisons.

Question 90: What is the ACE-V methodology used in latent print examination?

Archive, Catalog, Examine, and Version — the evidence logging system
Authenticate, Classify, Extract, and Validate — the AFIS search process
Acquire, Capture, Enhance, and Verify — the digital imaging process
Analysis, Comparison, Evaluation, and Verification — the scientific method for fingerprint examination (Correct answer)

Correct answer: Analysis, Comparison, Evaluation, and Verification — the scientific method for fingerprint examination

ACE-V (Analysis, Comparison, Evaluation, Verification) is the standardized scientific methodology used by latent print examiners to reach identification conclusions.

Question 91: What is the primary forensic value of botanical trace evidence such as pollen grains, seeds, or plant fragments?

Can associate a person, object, or vehicle with a specific geographic location or environment (Correct answer)
Identifies the type of weapon used
Determines the precise time of death of the victim
Establishes the victim's identity through DNA

Correct answer: Can associate a person, object, or vehicle with a specific geographic location or environment

Pollen, spores, and plant fragments are often geographically specific, allowing forensic botanists to link a suspect, victim, or item to a particular location or environment where those plants grow.

Question 92: An evidence technician notes a strong smell of accelerant at a fire scene. The first step should be to:

Photograph from inside the structure before any assessment
Pour water on suspected accelerant areas to stabilize them
Notify the fire investigator and ensure scene safety before collecting samples (Correct answer)
Immediately collect soil samples from all burned areas

Correct answer: Notify the fire investigator and ensure scene safety before collecting samples

Scene safety must be confirmed and the appropriate specialist notified before evidence collection begins at a fire scene.

Question 93: Which condition is most likely to degrade DNA quality in biological evidence collected from an outdoor crime scene?

Sealed paper packaging during transport
Immediate refrigeration after collection
Cold, dry storage conditions
Prolonged exposure to UV light, heat, and humidity (Correct answer)

Correct answer: Prolonged exposure to UV light, heat, and humidity

UV radiation, heat, and humidity are the primary environmental factors that cause DNA fragmentation and degradation in outdoor biological evidence.

Question 94: A wet bloodstain is found on a carpet at a crime scene. What is the proper initial collection method?

Cut out the carpet section and seal in a plastic bag
Absorb with a sterile swab and allow to air dry before packaging (Correct answer)
Photograph only and leave in place
Apply a chemical fixative immediately

Correct answer: Absorb with a sterile swab and allow to air dry before packaging

Wet biological stains should be collected with a sterile swab, air-dried to prevent mold growth, then packaged in breathable paper packaging.

Question 95: Which alternate light source wavelength range is commonly used to visualize fluorescent fingerprint powders?

Blue-green light (450–530 nm) with orange or yellow goggles (Correct answer)
Red light (600–700 nm) with green goggles
Infrared light (900 nm) with standard glasses
UV light at 254 nm with no goggles

Correct answer: Blue-green light (450–530 nm) with orange or yellow goggles

Fluorescent powders are typically excited by blue-green light (around 450–530 nm), and barrier goggles in the orange or yellow range block the excitation wavelength so only the fluorescence is visible.

Question 96: What is a stipulation in criminal court proceedings and how can it simplify evidence technician testimony?

A written summary of evidence submitted in place of live testimony
An agreement between prosecution and defense to accept certain facts as true without requiring testimony, reducing the need for the technician to take the stand (Correct answer)
A pre-trial agreement to exclude certain evidence from consideration
A court order requiring the technician to testify about specific topics only

Correct answer: An agreement between prosecution and defense to accept certain facts as true without requiring testimony, reducing the need for the technician to take the stand

Stipulations are agreements by both parties to accept certain facts (e.g., chain of custody for routine lab analysis) as established, often eliminating the need for the evidence technician to testify about those points.

Question 97: What does a forensic toxicology report primarily establish in a criminal investigation?

The psychological profile of the suspect
The timeline of events at the crime scene
The presence, identity, and concentration of substances in biological specimens (Correct answer)
The manner of death as determined by a coroner

Correct answer: The presence, identity, and concentration of substances in biological specimens

Forensic toxicology analyzes biological specimens such as blood and urine to detect, identify, and quantify drugs, alcohol, and poisons.

Question 98: Which presumptive test is used to detect the presence of seminal fluid at a crime scene?

Benzidine test
Kastle-Meyer test
Luminol test
Acid phosphatase test (Correct answer)

Correct answer: Acid phosphatase test

The acid phosphatase test detects the enzyme acid phosphatase found in high concentrations in seminal fluid; a positive result turns the reagent purple.

Question 99: Which container is MOST appropriate for storing soil samples collected from a crime scene?

Paper envelope
Sealed glass jar or metal can (Correct answer)
Biohazard bag
Plastic zip-lock bag

Correct answer: Sealed glass jar or metal can

Glass jars or metal cans preserve volatile compounds in soil samples better than plastic, which can absorb or off-gas trace chemicals.

Question 100: An evidence technician finds a bloody print at a scene. Which technique should be used to enhance it?

Standard fingerprint powder
Ninhydrin application
Amido black or leuco crystal violet staining (Correct answer)
Cyanoacrylate fuming

Correct answer: Amido black or leuco crystal violet staining

Amido black and leuco crystal violet react with proteins in blood to intensify and enhance bloody prints for photography and comparison.

Evidence Technician Certification (ETC)

The Evidence Technician Certification (ETC) validates a candidate's knowledge of forensic evidence collection, processing, and preservation procedures including crime scene processing, fingerprint analysis, biological/DNA evidence handling, and courtroom testimony requirements.

Questions

35 min

Time Limit

70%

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