Wildland Fire Investigation, FI–210 Origin and Cause Determination

4-3 Fire Investigation – Causes
In simple terms, fire investigation is the discovery of the circumstances, conditions and
sequence of events that caused the fire.
Applying the scientific method merely goes into a little more detail. There has been a fire, and
you, the investigator, must determine the cause. You study burn patterns, assess any physical evidence
you find at the scene, and analyze all the fire behavior data collected from firefighter reports. Once you
have studied all the facts, formulate a working hypothesis as to how the fire started. Begin with the
simplest, most logical explanation, then test your hypothesis with scientific data to see if it’s sound and
explains all the facts in evidence. If it does, this becomes your final hypothesis and you can complete
your report. If not, you must go back and re-analyze the data until you find the correct cause.
• A fire investigation is the discovery of the circumstances, conditions, and sequence of events
that bring together fuel and an ignition source to cause a fire.
4-4 Fire Investigation – Right to Privacy
Attorney Melvin Belli once said, “If your investigator is good enough, almost any attorney will
do.” As a fire investigator you are the one responsible for determining the cause of the fire, and in the
event of any legal challenges you may be called upon to defend your determination in court. So while you
are applying scientific methodology to determine the cause, you must also be sure that, where applicable,
you follow all NFPA legal guidelines and ensure that all your actions are based on a sound Constitutional
foundation.
“The right of the people to be secure in their persons, houses, papers, and effects, against
unreasonable searches and seizures, shall not be violated...”
Fourth Amendment, US Constitution
4-5 Fire Investigation – Reasonable Expectation
When you conduct a fire origin and cause investigation you are searching for evidence, but
before you can seize anything relevant you must consider the legal question of whether the search was
reasonable, and whether the subject of the search has a reasonable expectation of privacy under the 4th
Amendment. The answer to this question lies in where you are searching and exactly what you plan to
seize.
It’s up to the courts to define what is reasonable, and that definition may change over time as
new rulings are made. If the court rules that any evidence was seized in violation of current standards,
it will be excluded from those proceedings, which means that particular evidence cannot be used in
civil or criminal court proceedings.
court.
If the court rules certain evidence is excluded, that evidence cannot be used in civil or criminal
Application of the Fourth Amendment: