Fire Investigation Expert Witness Case Study 3

Independent forensic expert evidence in a fire investigation

Bericon Forensics was instructed to provide independent forensic expert witness evidence in a case involving a fire at a residential property.

The occupant stated that she had seen a bright light near the letterbox and had then extinguished a fire. A thin polyester and cotton curtain had been suspended behind the front door as a draught barrier.

It was alleged that the occupant had deliberately set fire to the curtain and allowed it to burn beyond the letterbox before pulling it down and extinguishing it. Suggested motives included self-harm or creating evidence of harassment.

The forensic expert’s instructions

A forensic fire investigation expert was asked to review the proposed ignition mechanism and consider whether the fire could have been started from outside the property.

The forensic expert examined:

• the position and construction of the letterbox;
• the location of the curtain behind the front door;
• the likely point of ignition;
• the behaviour of the curtain material when exposed to flame;
• the damage to the plastic letterbox flap; and
• the prosecution’s explanation for how the fire had started.

Independent forensic fire investigation

The prosecution had presented a credible explanation for the fire. However, the forensic expert identified a second possible mechanism that required further investigation.

Tests showed that it would have been extremely difficult to light a match or conventional cigarette lighter through a spring-loaded letterbox. Doing so would require both flaps to be held open while a hand and lower arm were passed through the narrow opening to operate the ignition source.

The forensic expert then considered whether a gas-powered lighting wand could have been used from outside the property.

Testing demonstrated that the metal wand could be passed through the letterbox far enough to hold the internal flap open and bring the flame into contact with the curtain.

The curtain material could then ignite rapidly and burn upwards from the point of ignition, causing heat damage and melting to the plastic letterbox flap.

Expert witness conclusion

The forensic fire expert witness concluded that ignition from outside the property using a gas-powered lighting wand was a credible alternative explanation for the fire.

The scientific testing showed that the physical evidence was capable of supporting more than one possible account of how the fire had started.

Case outcome

The alternative ignition mechanism was accepted by the prosecution as credible. Faced with two possible explanations for the fire, the case was not proceeded with.

This case demonstrates how an independent forensic expert witness can test an alleged fire mechanism, identify realistic alternative explanations and clarify the limits of the physical evidence.

Instruct a fire investigation expert witness

Bericon Forensics provides access to experienced forensic experts and expert witnesses for criminal cases involving:

• fire scene investigation;
• origin and cause of fire;
• alleged deliberate ignition;
• testing of proposed fire mechanisms;
• flammability and fire behaviour;
• review of prosecution fire reports;
• alternative ignition scenarios; and
• independent expert witness reports.

Our forensic fire experts can assess the available evidence, test proposed explanations and prepare clear reports for solicitors, counsel and the court.

Contact Bericon Forensics to discuss the instruction of a fire investigation expert witness.