The 1998 murder of an 18-year-old freshman Kalee Bruce, who was studying at Northwest Michigan College and working as a clerk at the Beach Condominiums. She was savagely beaten and stabbed to death by a person later identified as Kevin Holtzer

The case of Arkansas teenager Kacie Woody, who fell prey to her killer after discovering internet chat rooms

The case of 17-year-old rising social media star and high school athlete Alexis Murphy who disappeared in August 2013 along the Route 29 in Virginia. A massive search by local and federal authorities yielded nothing, until a security video offered a chilling clue. Plus, the case of 18-year-old student Hannah Graham, who vanished in the same area in September 2014

In August 1992, millionaire Tennessee landowner Allen Roberts arrived home to discover his wife was missing. He told police he had received a ransom call for Doe's safe return. Slowly, the town turned on Allen - until police took note of one 'odd-ball' neighbour

The case of 24-year-old Megan Sharpton, who was raped and murdered before her body was set alight in July 2012. The torment led to her mother committing suicide

The murders of retired Michigan police officer Michael Greene and his wife Terri in their home. Police found evidence of a personal grudge as a possible motive for the crime

Buying goods from the comfort of home

Buying goods from the comfort of home

Buying goods from the comfort of home

Buying goods from the comfort of home

The murders of retired Michigan police officer Michael Greene and his wife Terri in their home. Police found evidence of a personal grudge as a possible motive for the crime

A respected police officer shot on his way home from work. Plus, a young man found dead in his bed. In both cases, police had to determine what had happened to these men

A case in which 20-year-old disappeared when travelling from her fiance's home. Investigators suspected that someone from law enforcement might be responsible

In 1992, a college student disappeared after her car broke down on a main road. Police were stumped when her body was found 500 miles from where she vanished

A case with origins in the deaths of three men over a span of a dozen years, with no suspicion of wrongdoing and no files charged. However, when a deadly car explosion ripped through downtown Pensacola, Florida, a new investigation began, with growing suspicions pointing toward just one person

A case in which two 20-year-olds suffered personal tragedies - then had their own lives abruptly snuffed out. One was shot while hanging out with friends, while the other disappeared, only to turn up dead in a staged suicide. Their families set out to prove what really happened

The murder of a pregnant woman, killed while delivering newspapers. Detectives weighed up whether strangers were responsible, or if the culprits were known to the victim

The disappearance of a young pilot in the mountains of Colorado, who left her baby behind. Police unravelled a story far more horrifying than they imagined

A case in which a burning car was found by the side of a road on the same night a mother of two was reported missing. The two events led investigators to a notorious criminal

The 1989 murder of rising Hollywood star Rebecca Schaeffer. Detectives set out to determine who had killed the 21-year-old actress, and questioned whether a copycat killer was on the loose. Eventually they were led to Robert John Bardo, a fan who had been stalking her for three years