CFI Investigative Planning & Methodology 3 — Questions and Answers
Question 1: In the context of investigative methodology, what does 'negative corpus' mean and why is it problematic?
- A finding that no accelerants were detected, confirming accidental cause
- Concluding a fire was incendiary solely because no accidental cause was found (Correct answer)
- A forensic report that lacks physical evidence samples
- The absence of witness testimony in an investigation
Correct answer: Concluding a fire was incendiary solely because no accidental cause was found
NFPA 921 warns against negative corpus — declaring incendiary origin simply by eliminating accidental causes without positive proof of an intentional act.
Question 2: Which of the following best describes a 'working hypothesis' in fire investigation methodology?
- The final conclusion submitted in the investigative report
- A tentative explanation consistent with known data, subject to revision (Correct answer)
- An assumption accepted without requiring evidentiary support
- A legal finding of probable cause presented to a prosecutor
Correct answer: A tentative explanation consistent with known data, subject to revision
A working hypothesis is a provisional explanation that guides the investigation and must be tested and revised as new data emerges.
Question 3: When establishing the sequence of events during investigative planning, which type of timeline is MOST useful?
- A timeline based solely on 911 call records
- A composite timeline integrating witness accounts, alarm data, and physical evidence (Correct answer)
- A timeline limited to the suppression phase activities
- A timeline constructed from insurance claim documents
Correct answer: A composite timeline integrating witness accounts, alarm data, and physical evidence
A composite timeline merges multiple data sources to establish the most accurate and defensible sequence of events leading up to and during the fire.
Question 4: A CFI suspects electrical involvement in a fire. Which methodological step should follow the initial hypothesis?
- Immediately classify the fire as accidental in the report
- Identify and collect all potential electrical evidence for further analysis (Correct answer)
- Defer to the utility company's internal investigation findings
- Request that the scene be cleared and the structure demolished
Correct answer: Identify and collect all potential electrical evidence for further analysis
After forming an electrical hypothesis, the investigator must gather all relevant electrical evidence to test and support or refute that hypothesis.
Question 5: Which of the following represents a common methodological error that can invalidate a fire investigation?
- Reviewing building permit records before the physical examination
- Forming a cause conclusion before completing the scene examination (Correct answer)
- Using multiple experts to evaluate complex fire patterns
- Conducting witness interviews in a neutral location
Correct answer: Forming a cause conclusion before completing the scene examination
Premature conclusions create confirmation bias, causing investigators to selectively gather evidence supporting that conclusion rather than objectively evaluating all data.
Question 6: What is the primary purpose of an investigative scope statement prepared before a fire investigation?
- To satisfy insurance company documentation requirements
- To define boundaries, objectives, and resources needed for the investigation (Correct answer)
- To provide the media with an official statement about the fire
- To establish criminal liability before the physical examination begins
Correct answer: To define boundaries, objectives, and resources needed for the investigation
A scope statement clarifies what the investigation will and will not address, allocates resources appropriately, and sets measurable objectives.
Question 7: During investigative planning for a suspected arson case, which resource is MOST valuable for understanding the building's construction before site entry?
- Social media posts from witnesses
- Architectural drawings, building permits, and occupancy records (Correct answer)
- Insurance adjuster's preliminary loss estimate
- News media footage taken during suppression
Correct answer: Architectural drawings, building permits, and occupancy records
Architectural drawings and building records reveal construction type, fuel load distribution, and compartmentation, which directly inform fire behavior analysis.
CFI Investigative Planning & Methodology 3
In the context of investigative methodology, what does 'negative corpus' mean and why is it problematic?