A stray bullet kills 15-year-old La'Kyijah Williams, outraging Chief Eric Winstrom. CCTV shows a masked gunman, but witnesses refuse to talk

Solving a murder is hard enough. But what happens when detectives are faced with a perpetrator who knows how to stay one step ahead - a killer with a badge.

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

The murder of 31-year-old violinist Helen Mintiks, whose body was discovered in an airshaft at the Metropolitan Opera House in July 1980. A stage hand was later convicted of the crime, which happened after she rejected his sexual advances

A case in which a 23-year-old man went missing in Beech Island, South Carolina. As his family searched for him, an ominous text message deepened the mystery

A blood-stained bicycle hidden in an Ohio cornfield set the stage for an unspeakable crime. While police raced to find missing 20-year-old student Sierah Joughin, a vicious predator lurked somewhere in the rural, Midwestern countryside

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 murder of 31-year-old violinist Helen Mintiks, whose body was discovered in an airshaft at the Metropolitan Opera House in July 1980. A stage hand was later convicted of the crime, which happened after she rejected his sexual advances

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

After moving in with her new boyfriend, a woman was shot dead and an engaged couple murdered. Secrets from their pasts were sought to explain their deaths

A case in which the body of a musician was found in an alleyway and a construction worker disappeared on the job. Police searched for clues about these callous murders

How a quiet rural town was rocked when two middle school girls went on a hike and were later found murdered. When police discovered one of the girls may have recorded her killer with her cellphone, the race was on to find the killer

An air force veteran disappeared along with his savings of $206,000. Detectives discovered a woman had been draining his accounts, then uncovered a conspiracy of greed and murder

A college coed disappears, and her family launches a desperate investigation to find her. What they discover will change their lives forever.