Officers investigate the murder of Christoper Donovan by a gang of youths.

After going missing for a year and a half, many believed 14-year-old Cheyenne had run away from home. However, closer analysis revealed the tragic truth.

After finding her dead in a bathtub full of bleach, detectives narrowed down the killer from 210,000 possible suspects.

After a badly decomposed body was found in a suitcase by a railway embankment in Exeter, Police hunt for the killer with only CCTV evidence to go on.

In 1986, Detective David Baker became the first person to use DNA profiling in a criminal investigation, when looking for the killer of two young girls.

How the investigation into Phillip Inhofer at his home in Sacremento led police to a 20-year-old call girl known as Bat Girl.

How police used CCTV, eyewitness statements and a public appeal to find the killer of a 28-year old woman, found dead on Nottingham's streets

In 2002, police made a starling discovery inside a locked room in Anthony Hardy's home. This was merely a horrifying prelude for what was to come.

With no CCTV and no witnesses, detective Jon Buehler must find the person responsible for a drive-by shooting of "gentle giant" Sula Palega.

In 1981, detective Mike Southwell investigated a missing persons case that contained one of the grimmest discoveries in British police history