British Police: Our Toughest Cases - Season 1

A detective and a forensic scientist recount the murder case of Angelika Kluk in 2006 and how it came to be linked to one of Scotland's worst serial killers.

In 1991, 13 children collapsed in a Lincolnshire hospital - four of them died. DS Stuart Clifton reveals the chilling discovery that serving nurse Beverley Allitt was a child serial killer.

The case of five-year-old April Jones, who in 2012 disappeared while playing with friends in a Welsh village. DS Andy John recalls the hunt for her killer, who turned out to be 46-year-old local man Mark Bridger.

For 17 years, a serial attacker raped elderly victims in their own homes in south London. This documentary reveals how officers caught culprit Delroy Grant who operated in the area between October 1992 and May 2009.

In the 1980s and '90s, there were around 200 murders and attacks on sex workers across the Midlands. Stafford man Alun Kyte was later found to be responsible.

In 2009, the sleepy Norfolk village of Fakenham was hit with the horrific and brutal murder of 45-year-old Steven Murphy. Andrew Cameron and his friend Alexander Dewar denied the act, but were convicted by a jury at Norwich Crown Court.