NFPA 921
Fire & Explosion Investigation
The Scientific Method. Step 1
Recognize the need
The Scientific Method. Step 2
Define how the problem can be solved.
The Scientific Method. Step 3
Collect facts and Data
The Scientific Method. Step 4
Analyze Data by inductive reasoning
The Scientific Method. Step 5
Develop a Hypothesis to explain origin and cause of fire
The Scientific Method. Step 6
Test the Hypothesis. Compare to all known facts
The Scientific Method. Step 7
Select Final Hypothesis
Why is it important to follow the scientific method in a fire investigation?
The scientific method provides a systematic approach to data collection, analysis, and hypothesis testing that is an accepted framework for organizing your investigation and for presenting your process and findings to the court.
Recognize the need
1. Confirm a fire or explosion has occurred.
2. Confirm you are assigned to investigate.
3. Confirm your role and responsibilities.
4. Identify location.
Define the problem
1. Assess the incident and prepare.
2. Determine what tools, equipment, and personnel are needed.
3. Understand fire service response and actions.
4. Secure right of entry or obtain permission to enter scene.
5. Conduct scene safety inspection.
6. Secure
Collect Data
1. Interview first responders abut actions at the scene and conditions observed.
2. Conduct exterior examination.
3. Conduct interior examination.
4. Identify and interview witnesses.
5. Document and collect physical evidence.
6. Access document evidence
Analyze Data
1. Reconstruct area of origin.
2. Examine physical evidence.
3. Interpret fire effects and fire patterns.
4. Correlate witness statements.
5. Chart the timeline of events.
6. Examine all reasonable potential accidental causes.
7. Examine documents.
Develop a hypothesis
1. Develop a hypothesis of the origin and cause of the fire, based on the available facts collected and analyzed.
Test the Hypothesis
1. Eliminate all reasonable accidental causes.
2. Eliminate all other reasonable causes.
3. Consider all facts in relation to your hypothesis.
4. Test hypothesis against known physical facts and accepted fire dynamics theories.
5. Experiment or fire model
Select final hypothesis
1. Explain how arrived at.
2. Support with facts.
When employing the scientific method, how should you arrive at your conclusion about the origin and cause of a fire?
Let the observed facts dictate your fires hypothesis. Test that hypothesis based on facts you observe, updating it as you collect more data. Develop a series of hypotheses, including all reasonable accidental and non-accidental causes, and test each by de
Court Case Frye VS United States
In response to "junk science" being offered as testimony, this decision set the first standard for admissibility of expert testimony as "general acceptance in a particular field.
Court Case Kumho Tire vs Carmichael
This decision stated that the four flexible criteria for admissibility of expert testimony applies not only to scientific testimony, but also to technical or other specialized knowledge that is not purely scientific.
Court Case Benfield
This decision applied the four criteria to the testimony one expert who held himself out to be a scientist, but not to the testimony of another expert who did not.
Court Case Daubert
This decision further developed the criteria for admissibility of expert testimony that may be applied by the trial judge to four factors: testing, rates of error, peer review, and general acceptance in a scientific community.
NFPA 1033
4.1.2
The fire investigator shall employ all elements of the scientific method as the operating analytical process throughout the investigation and for the drawing of conclusions.
NFPA 1033
4.6.5
Formulate an opinion concerning origin, cause, or responsibility for the fire, given all investigative findings, so that the opinion regarding origin, cause or responsibility for a fire is supported by the data, facts, records, reports, documents, and evi
A.4.6.5
For additional information regarding evaluation methods see, ASTM E678, Standard practice for evaluation of technical data.
NFPA 921, Chapter 4
Basic Methodology
NFPA 921, Chapter 4
4.1
Nature of Fire Investigation.
1. Should be accomplished objectively, truthfully, and without expectation bias, preconception, or prejudice.
2. The basic methodology of the fire investigation should rely on the use of systematic approach and attention to a
NFPA 921, Chapter 4
4.2
Systematic Approach
1. The systematic approach recommended is that of the scientific method, which is used in the physical sciences.
NFPA 921, Chapter 4
4.3
Relating Fire Investigation to Scientific method