Evidence Technician Certification (ETC) — Questions and Answers

Question 1: When collecting swabs from multiple locations at a crime scene for biological evidence, why must a new swab be used for each location?

To comply with OSHA biohazard disposal requirements
To maintain the correct swab-to-sample ratio for lab analysis
Because swabs are single-use due to cost regulations
To prevent cross-contamination between locations, which could produce mixed DNA profiles and confuse the investigation (Correct answer)

Correct answer: To prevent cross-contamination between locations, which could produce mixed DNA profiles and confuse the investigation

Using a separate swab for each location prevents cross-contamination, which could create mixed DNA profiles that make it impossible to determine which DNA came from which location.

Question 2: At an outdoor homicide scene, what environmental factor poses the greatest threat to trace DNA evidence?

UV radiation and moisture (Correct answer)
Wind direction
Ambient noise levels
Soil pH

Correct answer: UV radiation and moisture

UV radiation breaks down DNA strands and moisture accelerates microbial degradation, making them the primary environmental threats to trace DNA.

Question 3: Why must forensic analysts wear PPE including gloves and masks when handling evidence?

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

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

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

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 5: An evidence technician recovers a projectile from a crime scene. Which lab discipline would perform the analysis?

Toxicology
Serology
Firearm and toolmark examination (Correct answer)
Trace evidence analysis

Correct answer: Firearm and toolmark examination

Firearm and toolmark examiners analyze bullets, casings, and other projectiles to link them to specific weapons or determine trajectory.

Question 6: What is the purpose of creating a forensic image (bit-stream copy) rather than simply copying files from a digital device?

A forensic image is faster than copying files manually
A forensic image captures every bit including deleted files, slack space, and unallocated sectors that file copying misses (Correct answer)
A forensic image creates a compressed archive for storage efficiency
A forensic image automatically decrypts protected files

Correct answer: A forensic image captures every bit including deleted files, slack space, and unallocated sectors that file copying misses

A bit-stream forensic image copies every sector of the media, preserving deleted files, file system metadata, slack space, and unallocated areas that simple file copying skips.

Question 7: Which federal law governs the interception of electronic communications and must be considered when collecting digital evidence?

Computer Fraud and Abuse Act (CFAA) only
Electronic Communications Privacy Act (ECPA) and the Wiretap Act (Correct answer)
Fourth Amendment only
Sarbanes-Oxley Act (SOX)

Correct answer: Electronic Communications Privacy Act (ECPA) and the Wiretap Act

The ECPA and Wiretap Act govern the collection and use of stored and intercepted electronic communications, requiring proper legal authority before accessing such data.

Question 8: Why is it important to place a cell phone in a Faraday bag or airplane mode immediately upon seizure?

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

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 9: What is the delta in a fingerprint pattern?

A bifurcation minutiae point
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

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 10: Which biological sample from a suspect provides the longest window for detecting alcohol consumption?

Saliva (up to 24 hours)
Blood (up to 12 hours)
Urine (up to 80 hours)
Hair (EtG in hair — up to 90 days) (Correct answer)

Correct answer: Hair (EtG in hair — up to 90 days)

Ethyl glucuronide (EtG) incorporated into hair can detect alcohol consumption for up to 90 days, far exceeding blood, urine, or saliva windows.

Question 11: 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 undercarriage
The engine compartment
The interior door panels

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

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

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 13: What is required for physical evidence to be authenticated before it is admitted in court?

Two independent witnesses who observed the collection
Sufficient evidence that the item is what it is claimed to be, typically established through chain of custody and witness identification (Correct answer)
Certification by a state-licensed forensic laboratory only
A signed affidavit from the prosecuting attorney

Correct answer: Sufficient evidence that the item is what it is claimed to be, typically established through chain of custody and witness identification

Authentication requires presenting sufficient evidence that the item is what the proponent claims; chain of custody records and testimony from the collecting officer typically satisfy this requirement.

Question 14: Which microscopy technique is used to compare tool marks and bullet striations in forensic firearm analysis?

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

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 15: A technician is casting a tire track in soft soil. Which material is most commonly used?

Plaster of Paris
Dental stone (die stone) (Correct answer)
Liquid latex
Silicone rubber

Correct answer: Dental stone (die stone)

Dental stone is preferred over plaster of Paris for tire and shoe impression casting because it is harder, more durable, and captures finer detail.

Question 16: What is the significance of the term 'continuous chain of custody' in evidence management?

The same officer handles the evidence from collection to court
Evidence is monitored 24 hours a day by security cameras
Evidence is never moved once it enters the evidence room
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 17: What is the primary forensic value of botanical trace evidence such as pollen grains, seeds, or plant fragments?

Determines the precise time of death of the victim
Identifies the type of weapon used
Can associate a person, object, or vehicle with a specific geographic location or environment (Correct answer)
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 18: When an evidence technician testifies in court, which document serves as the foundation for their testimony about evidence handling?

The chain of custody form and associated documentation (Correct answer)
The suspect's booking record
The detective's case notes
The prosecutor's case file

Correct answer: The chain of custody form and associated documentation

The chain of custody form and associated documentation are the primary records used to support an evidence technician's court testimony about evidence handling.

Question 19: Cyanoacrylate (superglue) fuming is primarily used to develop latent prints on which type of surface?

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

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 20: 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
Latent print
Plastic (impression) print (Correct answer)

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 21: A freeze-thaw cycle occurring in an improperly stored biological sample PRIMARILY causes:

Cell lysis and degradation of genetic material (Correct answer)
Enhanced DNA amplification
Increased microbial activity
Stabilization of volatile compounds

Correct answer: Cell lysis and degradation of genetic material

Repeated freeze-thaw cycles rupture cell membranes through ice crystal formation, releasing enzymes that degrade DNA and compromise the evidentiary value of the sample.

Question 22: Which action would MOST compromise the integrity of digital evidence found on a computer at a crime scene?

Documenting the cable connections
Placing the device in an anti-static bag
Photographing the screen before shutdown
Powering on the computer to check its contents (Correct answer)

Correct answer: Powering on the computer to check its contents

Powering on a computer can alter timestamps, overwrite temporary files, and activate encryption, destroying critical digital evidence.

Question 23: What is the significance of a 'blank' sample in forensic laboratory analysis?

It detects contamination by confirming no target substances are in the testing environment (Correct answer)
It calibrates the weight of the evidence package
It serves as a duplicate of the primary evidence sample
It represents an unknown sample from the crime scene

Correct answer: It detects contamination by confirming no target substances are in the testing environment

A blank sample contains no target analyte and is processed alongside evidence to confirm the testing environment and reagents are not contaminated.

Question 24: The 'strip search' (or grid) method is most appropriate for crime scene searching when:

Only a single technician is available
The evidence is known to be liquid-based
The scene is very small and confined
The scene is large and open terrain requires thorough coverage (Correct answer)

Correct answer: The scene is large and open terrain requires thorough coverage

The strip/grid method is designed for large open areas, systematically covering terrain in parallel lanes to ensure complete coverage.

Question 25: 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 26: Which container is MOST appropriate for storing soil samples collected from a crime scene?

Sealed glass jar or metal can (Correct answer)
Biohazard bag
Paper envelope
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 27: What is the maximum recommended storage time for urine drug evidence samples at 4°C before analysis?

24 hours
3 days
7 days (Correct answer)
30 days

Correct answer: 7 days

Urine drug samples are generally stable at 4°C for up to 7 days; longer storage requires freezing to prevent bacterial growth and compound degradation.

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

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

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

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: When is it appropriate to collect elimination prints from individuals at a crime scene?

From anyone with legitimate access to the scene who may have left prints (Correct answer)
Only from suspects with prior criminal records
Only from the homeowner or property manager
Never, as it violates privacy rights

Correct answer: From anyone with legitimate access to the scene who may have left prints

Elimination prints are collected from anyone with lawful access to the scene to help identify and exclude non-suspect latent prints found during processing.

Question 31: What laboratory accreditation standard do most US forensic labs seek to ensure quality and competency?

ASCLD/LAB or ISO/IEC 17025 accreditation (Correct answer)
Joint Commission accreditation
OSHA 1910 compliance certification
FDA Good Laboratory Practice (GLP)

Correct answer: ASCLD/LAB or ISO/IEC 17025 accreditation

ASCLD accreditation and ISO/IEC 17025 certification are the primary standards demonstrating that a forensic lab meets technical competency and quality management requirements.

Question 32: An evidence technician discovers that a sealed package of drug evidence has been opened and resealed without documentation. This is BEST described as a:

Contamination event
Break in the chain of custody (Correct answer)
Normal evidence review procedure
Minor administrative error

Correct answer: Break in the chain of custody

Unauthorized opening and resealing without documentation constitutes a break in the chain of custody, which may render the evidence inadmissible.

Question 33: 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
Each person who handles the lift must sign and date, documenting the transfer to maintain an unbroken chain (Correct answer)
Lift cards are exempt from chain of custody because they are copies
Only the submitting officer needs to sign the lift card

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 34: What does the term 'evidence purge' refer to in an evidence management context?

Returning evidence to its owner without documentation
The authorized disposal of evidence no longer needed for legal proceedings (Correct answer)
Cleaning and decontaminating the evidence room
Removing duplicate entries from the database

Correct answer: The authorized disposal of evidence no longer needed for legal proceedings

An evidence purge is the authorized, documented process of disposing of evidence after all legal proceedings are concluded and retention periods have been met.

Question 35: Which step is performed LAST when processing a latent fingerprint with cyanoacrylate (super glue) fuming?

Heating the cyanoacrylate source
Photographing the developed prints (Correct answer)
Sealing the item in a fuming chamber
Applying dye stain to enhance contrast

Correct answer: Photographing the developed prints

After cyanoacrylate fuming develops the print and optional dye staining enhances contrast, the final step is photography to document the result.

Question 36: Which chemical method uses the ninhydrin reaction to develop latent prints on paper documents in a dry environment?

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

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

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

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

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

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 39: What is the Frye standard in relation to scientific evidence admissibility?

Scientific evidence only requires peer review to be admissible
Scientific evidence is admissible if the judge determines it is reliable based on specific criteria
Any scientific test result is automatically admissible as documentary evidence
Scientific evidence is admissible if the methodology is generally accepted in the relevant scientific community (Correct answer)

Correct answer: Scientific evidence is admissible if the methodology is generally accepted in the relevant scientific community

The Frye standard holds that scientific techniques must be generally accepted by the relevant scientific community to be admissible; some states still use Frye while federal courts use Daubert.

Question 40: When lifting a developed latent fingerprint with tape, what should be done immediately after lifting?

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

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 41: Which of the following is a critical component of long-term evidence preservation?

Frequent handling
Unrestricted access
Climate control and auditing (Correct answer)
Leaving items unsealed

Correct answer: Climate control and auditing

Long-term evidence preservation relies heavily on climate control to prevent degradation caused by temperature and humidity fluctuations. Regular auditing ensures that evidence is accounted for, stored correctly, and that the chain of custody remains intact. These measures collectively maintain the evidence's integrity and legal validity over extended periods.

Question 42: What is the forensic significance of finding bi-directional trace evidence transfer between two individuals?

It shows the samples are contaminated and unusable
It indicates the evidence was planted or staged
It proves guilt beyond a reasonable doubt
It strongly suggests direct physical contact between the two individuals (Correct answer)

Correct answer: It strongly suggests direct physical contact between the two individuals

Mutual exchange of trace materials — where each person's fibers or hair are found on the other — is highly consistent with direct physical contact and is difficult to explain through secondary transfer alone.

Question 43: When a deceased person is found at a scene, who has authority to authorize movement of the body for evidence collection purposes?

The medical examiner or coroner (Correct answer)
The lead evidence technician
The first officer on scene
The senior detective

Correct answer: The medical examiner or coroner

The medical examiner or coroner has legal jurisdiction over the body and must authorize its movement; the body remains under their authority until released.

Question 44: Which type of analysis uses ninhydrin reagent to develop latent fingerprints on porous surfaces such as paper?

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

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

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

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.

Question 46: Which reagent is used as a presumptive test for blood that produces a luminescent reaction?

Leuco Malachite Green
Phenolphthalein (Kastle-Meyer)
Luminol (Correct answer)
Hemastix strips

Correct answer: Luminol

Luminol reacts with the iron in hemoglobin to produce chemiluminescence, allowing detection of blood even when diluted or cleaned.

Question 47: When an evidence technician testifies in court, what is the primary purpose of their testimony?

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
To advocate for the prosecution's theory of the case

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

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

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 49: How should firearms be stored as evidence?

In plastic bags with ammunition
In open display cases
With evidence from other cases
Unloaded in secure locked storage (Correct answer)

Correct answer: Unloaded in secure locked storage

Firearms collected as evidence must always be rendered safe by unloading them before storage to prevent accidental discharge. They should then be placed in secure, locked storage, separate from ammunition, to maintain safety, prevent tampering, and preserve their evidentiary value. This ensures both handler safety and evidence integrity.

Question 50: During the collection of drug evidence, why should each pill, capsule, or powdered substance be packaged separately?

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

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

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

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

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

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 53: What is the primary purpose of documentation in evidence handling?

To support media publications
To maintain integrity and legal validity (Correct answer)
To make notes colorful
To replace photography

Correct answer: To maintain integrity and legal validity

Documentation in evidence handling creates a detailed, verifiable record of every step taken with a piece of evidence, from discovery to analysis and storage. This meticulous record-keeping ensures the evidence's integrity by demonstrating that it has been properly handled and preserved. This is essential for its legal admissibility and credibility in court.

Question 54: What labeling is required on stored evidence containers?

Technician initials and item number
Only case number
Type of packaging used
Case number, description, date, and initials (Correct answer)

Correct answer: Case number, description, date, and initials

Stored evidence containers must be clearly labeled with essential information to ensure proper identification and tracking. This includes the case number, a detailed description of the item, the date of collection, and the initials of the collecting or packaging technician. This comprehensive labeling maintains the chain of custody and prevents mix-ups, ensuring evidence accountability.

Question 55: Which of the following best describes 'substrate control' in evidence collection?

Collecting a sample of the surface material near but not on the stain (Correct answer)
Documenting the background radiation level at the scene
Using a control swab to test the collection tool
Running a blank sample through the lab instrument

Correct answer: Collecting a sample of the surface material near but not on the stain

A substrate control is an unstained sample from the same surface material collected near the evidence to detect background contamination.

Question 56: What does the term 'chain of custody' mean specifically in the context of digital evidence?

The sequence of forensic tools used to analyze the evidence
The order in which digital files are recovered from a drive
A documented record of every person who accessed or handled the digital evidence from collection through court presentation (Correct answer)
The backup copies made of digital files during analysis

Correct answer: A documented record of every person who accessed or handled the digital evidence from collection through court presentation

Chain of custody for digital evidence tracks every person who handled or accessed the device or image, proving it has not been altered or tampered with.

Question 57: 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
Tissue builder injection or rehydration using softening solutions prior to inking (Correct answer)
Standard ink card rolling without modification
Casting with dental stone

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 58: What does 'integrity of evidence' refer to in the context of chain of custody?

The monetary value of the evidence
Ensuring evidence remains unaltered and accounted for from collection to court (Correct answer)
The strength of fingerprints on the evidence
How quickly the evidence was collected

Correct answer: Ensuring evidence remains unaltered and accounted for from collection to court

Integrity of evidence means the item remains unchanged and fully accounted for throughout its lifecycle from collection to courtroom presentation.

Question 59: Which factor is the PRIMARY consideration when selecting packaging for trace evidence such as hair and fibers?

Cost-effectiveness of packaging material
Waterproofing to protect against floods
Prevention of static charge that causes fibers to escape or transfer (Correct answer)
Package color for easy identification

Correct answer: Prevention of static charge that causes fibers to escape or transfer

Static electricity can cause trace fibers and hair to cling to or escape packaging, leading to loss or cross-contamination; anti-static packaging is therefore the primary concern.

Question 60: 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)
A French legal term for presenting closing arguments
The process of swearing in a witness before testimony
The reading of Miranda rights to a suspect

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

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

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

Hair cannot be used for comparison — only DNA extraction
A single hair is sufficient for all comparisons
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

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 63: Which body fluid is identified by the presence of p30 (PSA) protein confirmed by immunological testing?

Urine
Seminal fluid (Correct answer)
Saliva
Blood

Correct answer: Seminal fluid

p30, also known as prostate-specific antigen (PSA), is a protein found in semen and is used as a confirmatory marker for seminal fluid in sexual assault evidence.

Question 64: Which fingerprint development technique is most appropriate for latent prints on wet evidence?

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

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 65: Which tool is most appropriate for collecting dry, loose trace evidence such as glass fragments or paint chips from a surface?

Stiff-bristle brush
Adhesive tape roller
Moistened cotton swab
Forceps or fine-tipped tweezers (Correct answer)

Correct answer: Forceps or fine-tipped tweezers

Forceps or tweezers allow the technician to pick up individual fragments with precision, avoiding contamination and maintaining the integrity of each piece of trace evidence.

Question 66: When collecting soil samples as evidence, what is the recommended minimum number of samples to collect from a questioned area?

At least three samples from different areas of the questioned zone (Correct answer)
One composite sample from the center
A single sample of 500 grams minimum weight
Ten samples at fixed grid intervals

Correct answer: At least three samples from different areas of the questioned zone

Collecting at least three samples from different areas of the questioned zone captures variability and provides representative comparison material.

Question 67: When photographing a developed latent fingerprint, what must always be included in the frame?

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

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 68: What is the correct procedure when an evidence technician makes an error on a written evidence log?

Tear out the page and start over
Draw a single line through the error, initial it, and write the correct information (Correct answer)
Leave the error and add a separate note at the bottom
Use correction fluid to cover the error

Correct answer: Draw a single line through the error, initial it, and write the correct information

Errors on evidence logs must be corrected by drawing a single line through the mistake, initialing it, and writing the correct information to maintain a clear, unaltered audit trail.

Question 69: Which measurement technique produces the most accurate fixed-point locations on a crime scene sketch when no right-angle walls are available?

Baseline offset measurement only
Single-point measurement
Triangulation from two fixed reference points (Correct answer)
Polar coordinates from one reference point

Correct answer: Triangulation from two fixed reference points

Triangulation from two known fixed points provides a unique x-y location for any object, even in open or outdoor scenes without walls.

Question 70: What is touch DNA and from what type of evidence can it be collected?

DNA from skin cells deposited through touch — collectible from surfaces like doorknobs, weapons, and steering wheels (Correct answer)
DNA taken from decomposed remains only
DNA collected only from blood and saliva samples
A laboratory amplification technique for degraded DNA samples

Correct answer: DNA from skin cells deposited through touch — collectible from surfaces like doorknobs, weapons, and steering wheels

Touch DNA refers to trace skin cells (epithelial cells) left when a person touches a surface; it can be collected from any object a suspect may have handled.

Question 71: 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
Both types provide the same level of individual identification in forensic analysis
Nuclear DNA provides individual identification; mitochondrial DNA provides maternal lineage but is not individually unique (Correct answer)
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 72: What legal authority is generally required before law enforcement can search the contents of a seized digital device?

The same warrant used to search the physical premises
A search warrant specifically authorizing the search of the device's contents (Correct answer)
Verbal consent from any adult present at the scene
An arrest warrant for the device's owner

Correct answer: A search warrant specifically authorizing the search of the device's contents

Per Riley v. California (2014), the US Supreme Court ruled that law enforcement generally needs a separate search warrant to search the digital contents of a cell phone.

Question 73: Which of the following chain of custody documentation errors could render evidence inadmissible in court?

A gap in custody records where the evidence is unaccounted for (Correct answer)
Attaching the evidence tag to the outside of the bag rather than inside
Using a ballpoint pen instead of a felt-tip pen on the evidence tag
Using sequential evidence numbers instead of alphabetical codes

Correct answer: A gap in custody records where the evidence is unaccounted for

An unaccounted gap in chain of custody raises the possibility of tampering, which can lead a court to exclude the evidence.

Question 74: 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 75: What is the order of volatility in digital forensics, and why does it matter to evidence technicians?

Only non-volatile data has evidentiary value in court
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)
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 76: Why is it important to use a systematic search method?

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

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 77: 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 blood type and DNA profile of the victim
The approximate time of death based on drying patterns
The victim's medical history from antibody markers in blood

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

Standard optical microscopy only
FTIR spectroscopy and scanning electron microscopy with EDX (SEM-EDX) (Correct answer)
UV-Vis spectrophotometry alone
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 79: What are the three fundamental fingerprint pattern types recognized in classification systems?

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

Correct answer: Loops, whorls, and arches

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

Question 80: An evidence technician seizes a laptop that is encrypted with BitLocker. What should be done to preserve potential access?

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)
Immediately power it off and submit to the lab
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 81: When collecting soil samples as comparison trace evidence, what is the correct procedure?

Collect samples from multiple locations including control areas away from the scene (Correct answer)
Take a single large sample from near the victim
Collect only from the exact location where the suspect stood
Skip soil collection if the ground is dry

Correct answer: Collect samples from multiple locations including control areas away from the scene

Collecting samples from multiple locations — including known control areas — allows forensic geologists to compare the questioned soil to reference samples and assess significance.

Question 82: What is the exclusionary rule and how does it affect improperly collected evidence?

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

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

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 84: A tape lift is used at a crime scene primarily to:

Stabilize bloodstain patterns for transport
Preserve shoeprint impressions in soft soil
Collect loose hair, fibers, and small particles from surfaces (Correct answer)
Develop latent fingerprints on smooth surfaces

Correct answer: Collect loose hair, fibers, and small particles from surfaces

Tape lifts use the adhesive surface of clear tape pressed against clothing, seats, or other surfaces to capture loose trace materials that can then be examined microscopically.

Question 85: Which protocol governs the destruction or disposal of biological evidence after a case is adjudicated?

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

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 86: What is a minutiae point in fingerprint analysis?

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

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

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

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

Plastic bags are not tamper-evident enough for evidence 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

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

Red light (600–700 nm) with green goggles
Blue-green light (450–530 nm) with orange or yellow goggles (Correct answer)
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 90: Which type of evidence requires refrigeration at 2–8°C upon submission to the forensic laboratory?

Controlled substance powders
Firearms and ammunition
Biological samples such as blood, saliva, and semen swabs (Correct answer)
Questioned documents

Correct answer: Biological samples such as blood, saliva, and semen swabs

Biological samples degrade rapidly at room temperature; refrigeration at 2–8°C slows bacterial growth and enzymatic breakdown to preserve DNA integrity.

Question 91: Under what circumstances may an evidence technician conduct a warrantless search under the plain view doctrine?

Whenever the officer believes evidence is present, regardless of location
When the officer is lawfully present, the evidence is in plain view, and its incriminating nature is immediately apparent (Correct answer)
During any traffic stop without limitation
Only when the property owner gives verbal consent

Correct answer: When the officer is lawfully present, the evidence is in plain view, and its incriminating nature is immediately apparent

The plain view doctrine allows warrantless seizure when: (1) the officer is lawfully present at the location, (2) the item is in plain view, and (3) the incriminating character is immediately apparent.

Question 92: 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)
Scrape the stain into a plastic vial and seal immediately
Use adhesive tape to lift the stain and place on a backing card

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 93: 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 16 points is federally mandated
A minimum of 12 points is federally mandated
A minimum of 8 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 94: What is metadata and why is it important in digital evidence investigations?

The file name extension that indicates file type
The main content of a digital file such as text or images
A digital watermark added by forensic tools
Data about data — it includes creation dates, GPS coordinates, and author information that can place evidence in time and location (Correct answer)

Correct answer: Data about data — it includes creation dates, GPS coordinates, and author information that can place evidence in time and location

Metadata embedded in files (EXIF data in photos, document properties) can reveal when a file was created, modified, where it was taken (GPS), and by whom.

Question 95: What is the purpose of using tamper-evident tape on evidence packaging?

To identify the evidence item by color code
To provide visible indication if a package has been opened (Correct answer)
To waterproof the package
To hold multiple items together

Correct answer: To provide visible indication if a package has been opened

Tamper-evident tape leaves a visible pattern or void message if removed, providing proof that a package has been accessed without authorization.

Question 96: What type of bloodstain results from blood dripping into existing blood at a lower velocity?

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

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 97: How long must chain of custody documentation typically be retained after a case is fully adjudicated?

As specified by applicable statutes, often several years or permanently for serious felonies (Correct answer)
One year only
Until the next audit cycle
30 days

Correct answer: As specified by applicable statutes, often several years or permanently for serious felonies

Retention periods are governed by applicable statutes and agency policy, with serious felony documentation often retained permanently or for many years to support potential appeals.

Question 98: Which of the following best describes the 'zone search' method at a crime scene?

Dividing the scene into sectors and assigning each to a different searcher (Correct answer)
Searching in an expanding spiral from the center outward
Walking in parallel lines across the entire scene
Following the path the suspect likely traveled

Correct answer: Dividing the scene into sectors and assigning each to a different searcher

The zone search divides the scene into sectors assigned to individual searchers, reducing missed areas and overlapping coverage.

Question 99: 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 cost of the DNA analysis
The reputation of the lab that tested it
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 100: Which documentation method provides the most accurate spatial data for reconstructing a crime scene?

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

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.

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.

100

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120 min

Time Limit

70%

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