A massive explosion claims the life of a California farmhand. Authorities think it's an accidental death, but analysis of debris shows it's a bomb. Investigators have few suspects until they hear ominous rumors about a jealous rage.

When a beautiful college student is stabbed to death in her Knoxville apartment, suspicion immediately falls on her roommate. A bloody shoe print left by the killer exposes a murderer with no history of violence and no reason to kill.

Members of law enforcement in a quiet Texas county are targeted. Numerous suspects emerge, and murders continue as detectives race against time. Finally, a single bullet casing uncovers the bizarre motive for the murders: revenge.

An Illinois mother and her two young children are brutally murdered in their beds. Lurid threats are spray painted all over the walls of the crime scene. Detectives discover death threats sent to the family, exposing an unlikely killer.

A young Texas teenager and her boyfriend are brutally attacked on Valentine's Day. She is found dead while her boyfriend escapes. The case goes cold for nearly 50 years before a new forensic test exposes a family man with a dark secret.

Three Indiana construction workers are found shot dead at a work site. Detectives find few suspects, but have one key clue: one of the killers stepped in dog feces during the murders. If detectives can find his shoes, they've got their man

A Texas ex-con resolves to live a clean life after his release from prison. When he's later arrested and convicted for a bloody murder, he insists he's innocent. From behind bars, he's determined to use forensic science to prove his case.

An extremely successful California career woman keeps falling ill and doctors can't determine why. When she dies, they still have no explanation, until they find a key figure in her life who has been lying about his past.