CFI Origin & Cause Determination 2

Question 1

When multiple areas of origin are suspected, what does NFPA 921 say the investigator should do?

Accepted Answer

Document and analyze each area separately to determine if multiple independent ignitions occurred

Answer

NFPA 921 requires investigators to analyze each suspected area of origin independently to determine whether multiple independent ignitions or a single origin with unusual burn patterns explains the evidence.

Question 2

Which of the following best describes a 'low burn' indicator and its significance in origin determination?

Accepted Answer

Charring or burn damage near floor level that may indicate the fire's lowest point of origin

Answer

Low burns refer to fire damage near floor level and may indicate an origin point or accelerant use, though HVAC effects and normal fire behavior must also be considered.

Question 3

A fire investigator observes that glass windows on one side of a structure are crazed while those on the opposite side are not. What does this most likely indicate?

Accepted Answer

The crazed glass side experienced rapid, intense heat consistent with that side being closer to the origin

Answer

Crazed glass results from rapid heating and sudden cooling (e.g., from water application), and its location can help investigators determine directional heat exposure relative to the origin.

Question 4

In cause determination, what is the significance of identifying the 'competent ignition source'?

Accepted Answer

It identifies an energy source capable of igniting the first fuel ignited under the conditions present

Answer

A competent ignition source must have sufficient energy to ignite the first fuel ignited, and identifying it is a required element of fire cause determination per NFPA 921.

Question 5

What is the primary reason investigators should document fire patterns before overhaul begins?

Accepted Answer

Fire pattern evidence on surfaces is destroyed or obscured during overhaul operations

Answer

Overhaul operations disturb, move, and destroy fire pattern evidence on floors, walls, and ceilings, making pre-overhaul documentation critical to preserving origin and cause evidence.

(CFI) Certified Fire Investigator Practice Test

(CFI) Certified Fire Investigator Practice Test

CFI Origin & Cause Determination 2