NARRATOR: A hit and run driver tried to remove all evidence of the crime. The vehicle was repaired, washed, polished, vacuumed, then sold to a new owner. Was it possible that some forensic evidence...

NARRATOR: Two women, both murdered in the same state park, Indiana police feared it was the work of a serial killer until the forensic evidence pointed them into two different directions. [theme...

NARRATOR: In 1993, five men were ambushed at work as they got out of their car. One man was killed, two others critically injured. The gunman left behind a few spent shell casings, but little else....

NARRATOR: In Land O'Lakes, Wisconsin, it's rare to hear the siren of an ambulance. So the death of an otherwise healthy young woman was particularly troubling. To solve the mystery, a...

[music playing] NARRATOR: It was a case unlike most others. Forensic evidence proved the perpetrator broke out of the crime scene rather than breaking in. No one knew why, until some evidence on the...