Armed with a shovel, a camera and a hypothesis, John Cassidy searches for clues among fire wreckage.
The Colwood fire investigator has 20 years of experience and often begins the hunt as the fire still burns.
During his career Cassidy has attended about 9,000 calls, roughly 1,500 of them fires. He has investigated blazes in dumpsters, tree stumps, fields, vehicles and homes.
“Anything that burns we have to investigate,” said the 46-year-old.
Discovering the cause is a bit different from other investigations.
“Police investigations of a serious crime or assault leaves behind evidence like DNA or blood. But for us the whole process of a fire is destroying everything,” explained the Colwood assistant fire chief.
A sleuth on scene, Cassidy has a keen eye for clues such as uneven charring of wood or smoke and heat patterns. He assesses variables including weather and barometric pressure that could impact a fire. More often than not he eliminates potential causes, leading him to the initial spark.
“The whole process is narrowing things down,” Cassidy said. He first searches for the area of origin and then a point of origin.
Sometimes a giant V pattern will pinpoint the location, the pattern marked out in soot and heat damage.
Every fire is different, but often the area with the most damage is where it started, he said. “Every fire teaches you something different.”
A few years ago Cassidy attended a fire that started in a bed. Even through he never found the cigarette butt, the resident’s burned fingers provided the evidence.
“A lot of fire investigators start out helping a fire investigator mucking around at a fire scene,” he said. “I helped sift through all the fire debris and looked for clues.”