Forensic Files S10 E04 Up in Smoke

"No Witnesses. No Leads. No Problem."

When an elderly couple died in a suspicious house fire, their son became the prime suspect. The son insisted he was innocent; he said he tried to extinguish the fire by pouring water on it, but that only made it worse. Investigators turned to forensic science to determine if the fire had been set deliberately, or if it was an unfortunate accident.