CFC Forensic Science Principles & Investigative Methods 3 — Questions and Answers
Question 1: Under the Daubert standard, which factor is NOT typically considered when evaluating the admissibility of scientific expert testimony?
- Whether the theory has been peer-reviewed
- Whether the method has a known error rate
- The cost of the expert's services (Correct answer)
- Whether the theory is generally accepted in the scientific community
Correct answer: The cost of the expert's services
Daubert factors focus on scientific validity (testability, peer review, error rate, general acceptance) and do not consider the financial cost of obtaining expert testimony.
Question 2: In bloodstain pattern analysis, what does a low-velocity impact spatter typically indicate?
- A gunshot wound
- Dripping blood or a fall (Correct answer)
- A high-speed vehicle collision
- An explosion
Correct answer: Dripping blood or a fall
Low-velocity impact spatter produces large, circular stains with regular edges and is typically associated with dripping blood under gravity or minor blunt force.
Question 3: What is the primary advantage of using Short Tandem Repeat (STR) analysis in forensic DNA profiling?
- It can determine the age of a DNA sample with precision
- It generates a highly discriminating profile from small amounts of degraded DNA (Correct answer)
- It identifies the race and ethnicity of a contributor
- It is less expensive than all other DNA methods
Correct answer: It generates a highly discriminating profile from small amounts of degraded DNA
STR analysis examines the number of repeated sequences at multiple loci, providing highly discriminating profiles even from small or degraded biological samples.
Question 4: A forensic examiner finds tool marks on a pried window frame. This evidence is best classified as:
- Class evidence only, since all similar tools leave the same marks
- Individual evidence, since manufacturing imperfections make each tool unique (Correct answer)
- Testimonial evidence requiring witness verification
- Demonstrative evidence with no evidentiary value
Correct answer: Individual evidence, since manufacturing imperfections make each tool unique
Tool marks can be individualized because manufacturing defects and wear patterns create unique striations that allow a specific tool to be matched to a specific mark.
Question 5: What is the significance of rigor mortis in a forensic death investigation?
- It establishes the exact time of death
- It provides an estimate of the postmortem interval within a range of hours (Correct answer)
- It identifies the cause of death
- It confirms homicide versus natural death
Correct answer: It provides an estimate of the postmortem interval within a range of hours
Rigor mortis begins within 2–6 hours, peaks around 12 hours, and resolves within 24–48 hours, helping to estimate time since death but subject to environmental variables.
Question 6: Which forensic discipline is specifically concerned with the examination of questioned documents?
- Forensic odontology
- Forensic document examination (Correct answer)
- Forensic anthropology
- Forensic toxicology
Correct answer: Forensic document examination
Forensic document examination involves analysis of handwriting, signatures, ink, paper, alterations, and printing to authenticate or detect forgery in documents.
Question 7: A Certified Forensic Consultant is asked to testify about digital evidence. Which action is MOST important before presenting such evidence in court?
- Converting the digital files to printed paper copies
- Verifying hash values to confirm the evidence has not been altered since collection (Correct answer)
- Encrypting the evidence with proprietary software
- Obtaining a second opinion from law enforcement
Correct answer: Verifying hash values to confirm the evidence has not been altered since collection
Hash verification (MD5, SHA-256) confirms digital integrity by showing the evidence's current hash matches the hash recorded at collection, proving it is unaltered.
CFC Forensic Science Principles & Investigative Methods 3
Under the Daubert standard, which factor is NOT typically considered when evaluating the admissibility of scientific expert testimony?