In the middle of the night, police and paramedics are called to what they are told is a devastating car accident.

A police car executes a stop and search on a drugs courier. The cop who stops the car finds a bag with hundreds of thousands of pounds inside and seizes it as the proceeds of crime.

Patricia Coulton is found slumped in her car by a dog walker. She has been stabbed 15 times in a frenzied attack just yards from the care home in Berkshire where she works.

It's August 1988 and a parcel arrives at Pedigree Petfoods, containing a tin of their dog food which has been laced with poison and a ransom note demanding £100,000.

Valerie was a respected and decorated officer. But when petty jealousy and greed turn into an outlandish plot to murder two people, FBI investigators convince her boyfriend to go undercover and capture the evidence they need to put her behind bars.

When a woman is found nearby with critical injuries, investigators begin to piece together the story of a secret affair gone horrendously wrong; a jealous rage leaves one person dead and another facing up to years of their lying and cheating.

Valerie was a respected and decorated officer. But when petty jealousy and greed turn into an outlandish plot to murder two people, FBI investigators convince her boyfriend to go undercover and capture the evidence they need to put her behind bars.

David Carrick is one of the most prolific sex offenders the UK has ever seen. His campaign of rape, torture and humiliation of women was carried out over nearly two decades.

In 2010, 31-year-old police officer Adam Provan lied about his age to take 16-year-old Lauren Taylor out. He then sexually assaulted her in a park.

PC Lewis Edwards was a young officer with a bright future ahead of him. But behind closed doors, he was a dangerous and predatory paedophile, who used a fake Snapchat profile to groom young girls.

Adrian Trevor Moore was a respected and experienced cop in Western Australian Police. Nominated for officer of the year, no one in the community that he served suspected that behind closed doors he was a violent and sadistic rapist.