In 2000, Judy Southern arrived home from work and was shot by a gunman waiting within. Her husband Allen arrived shortly afterwards, called 911 to report his wife had been shot.
In 1996, Derrick Duehren returned to find his Oregon home burned to the ground. His wife's charred remains were later found in the rubble.
A driver said he couldn't have hit and killed a pedestrian because his Jeep had been sold months ago.
In 2006, Nevada politician Kathy Augustine died mysteriously during a hard-fought re-election campaign and the medical examiner could neither isolate the cause of death.
Police are able to create a composite sketch of a man burnt beyond recognition. But tracking the killer is more challenging.
In 2007, the Florida mobile home of Effie and Michael Ratley catches fire. Michael heroically rescues his wife and infant son. A month later, his wife is found beaten to death in a bedroom of his parents' home.
It's usually easy to determine how a criminal entered the crime scene. But in this case, it was far from clear. It looked like the killer vanished into thin air...and perhaps he had.
A wealthy man and his wife were attacked by three masked men outside their luxurious Louisiana home. He was shot dead and she was forced to open their hidden safe.
In 1987, the death of Crystal Purcell was considered an accident. Then in 2001, Barbara Purcell called police to suggest that her estranged husband had killed Crystal.
A brutal murder, lots of suspects and conflicting evidence but the forensics were clear on one thing: The killer knew his victim. And that alone gave investigators a head start.
A Michigan State University grad student disappeared and was presumed dead. With the help of a professor of geological sciences, police hoped to get the "dirt" on her killer.
The crime scene was especially violent: A couple had been shot to death. Was their teenage daughter complicit?
Security cameras in a casino tracked a young woman's movements until shortly before she disappeared. She was never seen again.
When a dedicated, well-respected teacher disappeared, police had to determine if she'd gone on vacation without telling anyone, or if she was the victim of foul play.
In 1996, Virginia Beach police arrive at the Makdessi apartment to find Elise Makdessi and her lover dead.
When DNA proves that a man who practically admits to a brutal attack is innocent, police wonder why he is willing to take the blame.
A young woman is found dead in her apartment. With little evidence at the scene, the case turns cold.
In 2006, Darlene VanderGiesen received threatening emails and then disappeared. Tracking the source of the emails led police to the home of Daphne Wright, where they believe a murder was committed.
In 1996, Virginia Beach police arrive at the Makdessi apartment to find Elise Makdessi and her lover dead.
In 1969, phone operator Diane Maxwell is murdered. Her brother promised he'd find out who was responsible.