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.
In 2008, college co-ed Jenna Verhaalen was found dead in her Bryan, Texas apartment. Petechial hemorrhages in her eyes indicated that she was strangled.
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.
When a little girl got sick and died, investigators were stumped. Was it an accident, an unexplained illness or murder?
In 1991, Grand Junction, Colorado is on edge after a series of deadly bombings kill two people and injure one more. Police race to find the culprit before he strikes again.
It was one of the most unusual cases in forensic history. Investigators had to find a way to solve a murder case with evidence which consisted of a squashed tomato found at the crime scene.
Volunteers and police spend weeks searching for a missing girl. A psychic later leads them to a field where the body was found.
Christina Sanoubane was murdered in her Cedar Rapids apartment after moving away from her abusive boyfriend.
A lifelong resident of the tiny town of Lefroy, Tasmania was murdered outside his own home. Robbery appeared to be the motive, but with no suspects, the investigation came to a halt.
In 2001, Ginger Hayes and her infant son Nicholas were abducted during a carjacking and the crime had been reported by a witness within minutes of occurrence.
A young, attractive hairdresser was sexually assaulted and murdered in her own beauty salon. The evidence at the crime scene didn't match any of the suspects and the case went cold for ten years.
In 1991, Dorothy Donovan was murdered in her Dover, Delaware home and police are skeptical when her son Charles Holden stated that she was murdered by a hitchhiker he had picked up.
In one of the most brazen crimes of the 20th century, the chairman of the Coors Brewing Company was kidnapped.
In 1986, Gary Dale Larson was stabbed to death in his Edmond, Oklahoma home and then the killer sexually assaulted Larson's girlfriend Janet Haynes.
In 1999, Patrick McRae was found dead in his Des Moines home and the crime scene was awash with blood.
In 2003, Tiffany Rowell and three of her friends were brutally murdered in affluent Clear Lake, Texas.
James Kenneth Elmen Jr. abducted Julie Estes, then 21, from the Southside convenience store where she worked in 1985.
Digital enhancement of security camera video shows that what appears to be a casual encounter is actually a forced abduction, leading to murder.
How did the stalker obtain the security system code for his victim's home? How did he steal her personal photographs? Police needed answers and they found them in the most unlikely of places.
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.