Before his arrest in 2005, serial arsonist Thomas Sweatt terrorized Washington, setting more than 300 fires that left two people dead and investigators with few clues.
Experts couldn't pinpoint how he created violent fires without being seen. One idea was that Sweatt used jugs of gasoline to start the fires. Police proved that theory at the ATF Fire Research Lab in Beltsville.
"The goal for us is to provide scientific support for investigations," says Brian Grove, a fire protection engineer.
A team of agents and engineers recreate, examine and tape high-profile blazes, helping solve cases nationwide and around the world. They bring science to what used to be largely anecdotal research.
"Historically, fire investigators relied on things that were passed down to them," Grove says. "For example, if there was a lot of burns on the floor, it meant there had to be an accelerant. Anecdotal techniques are no longer accepted."
The ATF conducts a simulated burn roughly once a month. NewsChannel 8 got a rare look at a demonstration burn of a fake living room.
In only five minutes, the room is destroyed. But hidden in the ashes are clues to help investigators determine an arson or an accident, helping gain a conviction or acquittal.
Special Agent Steve Avato has worked some of D.C.'s most complicated cases and says in every pile of embers there's a story.
"If we determine that the fire is intentionally set, then we'll do investigative things to help figure out who set the fire," Avato says.
Sweatt is serving a life-plus-136-years sentence. But the battle against arson continues.
In June, the ATF Fire Research Lab will celebrate its tenth anniversary in a war against violent criminals.