Series 2

Suffolk, England, 2006 - the corpses of two young prostitutes are discovered in a river outside the town of Ipswich. A manhunt begins, but under the noses of the police and the eyes of the press, three more women are killed in rapid succession. The search for the killer becomes international news, the world watching as the tragedy unfolds on 24 hour news. The police have a hard time, the killer is forensically aware and is killing at a faster rate than Jack the Ripper, but then a stupid mistake from his past brings him to the attention of the authorities. But the battle isn't over. The police have to bring the full force of the latest in forensic science to put the Suffolk Strangler behind bars.

Bradford, Northern England, 2009 - drug addicted prostitutes start to vanish from the streets of the city. Their families contact the police who put out a missing persons report but they do not reappear. It's not unusual for street workers to go missing in a big city but everything suddenly changes when the brazen murder of a woman is caught on the CCTV of a local block of flats. The killer is a 40-year-old local named Stephen Griffiths. He seems to be performing for the camera. His arrest reveals a truly horrifying story - a local PhD student of criminology who seeks fame through re-inventing himself as the most revolting, taboo-busting serial killer that he can create. He is responsible for the disappearance of the local prostitutes - victims in his quest to turn his dark fantasies into a grotesque reality.

The story of Joel Rifkin, a self-employed landscape gardener from East Meadow, Long Island, who murdered and dismembered 17 prostitutes during the late 1980s and early 1990s.

In the summer of 2001 the bodies of several prostitutes are found, unceremoniously dumped at the sides of St Louis' highways. For over a year, police and FBI are mystified as to who is behind the murders. But then in May 2002, someone claiming to be the killer sends the police a letter along with a map printed from a computer-mapping site. The map leads police to the remains of another body. What the killer doesn't realise is that he has unwittingly led the investigators right to his door. Police are able to trace the making of the map to a computer belonging to a Maury Troy Travis, a 36-year-old waiter born and raised in St. Louis. When police descend on his home, they uncover the true horror of Travis' crimes: a torture dungeon where he filmed his horrific abuse and even some of the murders of his victims. But before Travis can be charged and receive justice for his crimes, he commits suicide in his prison cell, leaving police and relatives of victims with unanswered questions.

William Bonin was the first man in California to be executed by lethal injection. His death in 1996 followed a conviction for the murder of 21 boys aged between 12 and 19 in just one frenzied year. He is estimated to have killed as many as double that. A truck driver and son of a bingo-addicted, alcoholic mother and compulsive gambling father, he was incarcerated in juvenile detention at a young age where he suffered his first rape. On his release he began molesting young boys - a crime that would see him imprisoned and consigned to a mental institution. He met a part-time magician, Vernon Butts, and struck up a deadly friendship that would see them recruit a small gang of accomplices and go on to rape and murder lone boys, often hitch-hiking in the southern Californian sunshine. His victims were attacked in the back of his van, named by investigators as "the Death Wagon" and dumped by the side of the freeway, earning him the title; "The Freeway Killer".

When police see a car weaving between lanes on a Californian highway late one night, they pull the car over. In the driver's seat is Randy Kraft. In the passenger seat is a dead body. In the boot is a list of names, and under the seat is a collection of photos of what look like dead bodies on a sofa. A former military airman, Kraft targeted marines and gay men, routinely sodomising and emasculating them before he killed them. The torture his victims endured became more and more extreme. A computer programmer with a high IQ, Kraft to this day maintains his innocence and despite the extensive evidence against him, denies killing anyone. He is currently appealing his death sentence in the Federal courts. Kraft now sits on Death Row in the infamous San Quentin prison, convicted of 16 counts of murder. Known as the "Scorecard Killer" because of a piece of paper he kept believed to be a death list of victims, conservative estimates allege he has killed at least 50 more. Others put his total body count at over 100.