For over 20 years, sex killer Joachim Kroll had been strangling women across northern Germany. He claimed an internal force drove him, picking women walking alone in the countryside. Many were strangled with their own clothes. Then he molested them. As his killing spree increased, he started to target younger and younger victims. But even this didn't satisfy him. He killed and cooked a cat, which only drove his desire to taste human flesh. His demons overpowered him into killing, dissecting and then eating a neighbour's 4-year-old daughter. But when he was unable to dispose of the evidence, he was picked up by the police. He was charged with 12 murders but admitted to 30, making him Germany's most prolific killer in decades.

When a body is found trussed up in the River Odra in western Poland, the police are baffled. The man has been starved and tortured, before being thrown alive into the river. It has all the hallmarks of a punishment beating. The murder investigation stalls until police discover an online murder story written by a Krystian Bala that bears similarities to the death of the man in the river. Bala has even published a book, an explicit cocktail of murder and pornography. Bala becomes the prime suspect

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.

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".

For two years the baby-faced killer Karol Kot terrorised the Polish city of Krakow. Unlike many serial killers he appeared to have no fixed modus operandi when targeting his victims, which made tracking him down difficult. He began his attacks on elderly women, but after a two-year break, he moved to attacking children. An 11 year old boy is found stabbed to death: the boy's internal organs have been punctured in the frenzied attack. A young girl is targeted shortly afterwards. Witness statements link a schoolboy with the crimes. The country is horrified. The killer is finally caught when he confides in a potential partner. His attempt to impress her backfires. Instead she's horrified and goes straight to the police. Once in custody, the schoolboy Kot reveals he drank the blood of his victims as they lay dying.

Fritz Honka quietly lived in Hamburg's red light district of St Pauli, picking up elderly prostitutes for the price of a glass of schnapps and a bed for the night. He began to lose his temper when the women declined his sexual perversions. He retaliated by strangling his victims. Disposing of the bodies presented a problem until he came up with the idea of dismembering them and storing the body parts in the roof space next to his flat. Had a freak house fire not crept up the building to expose his collection he might never have been caught. He claimed he had been instructed by London's Victorian Jack The Ripper to perform the murders. He was sectioned at a mental institute after being convicted of 1 murder and 4 manslaughters.

Between 1975 and 1983, brutal sex killer Pawel Tuchlin terrorised the region around Gdansk, Poland. Known as 'The Scorpion' for the swift deadliness of his attacks, he targeted women walking alone. Tuchlin struck without warning, felling his victims with hammer blows to the head before molesting their bodies. He killed 9 women and left 11 more gravely injured. But Tuchlin is also a thief: it was his greed and the theft of 4 piglets which eventually led police to his farm, and sent the Scorpion to the gallows.

Anatoly Onoprienko, 'The Terminator', earned his nickname from an unprecedented spree of mass killings in Ukraine. In just 4 months he slaughtered 43 people, entering households and murdering whole families at a time. Children and even babies fell victim to this merciless killer. Onoprienko claimed he was on a dark mission for supernatural powers, that he heard voices in his head telling him to kill. But in reality he killed to make money: his arrogance and avarice led to his downfall as police found over 100 trophies stolen from victims stashed in his apartment. Onoprienko is sentenced for 52 murders, making him one of the most prolific and evil serial killers of the century.

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.

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.

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.

Not all serial killers are the same. Some kill for pleasure, others for reward. Cult killer Robert Rozier stalks Miami. He and his associates murder and mutilate on their master’s orders. But one fateful mistake will bring Rozier to justice.

Miami 1986. While a drug war rages, crazed killer Manuel Pardo believes he is on a mission to clean up the streets. Guilty or innocent, no one is safe. The city’s underworld is under siege, but one mistake will bring the killer out of the shadows.

When police discover the body of a vagrant, they dismiss it as just another ‘Skid Row’ killing. But when they find a second corpse, then a third, they quickly realise they are dealing with a machete wielding maniac… who won’t stop until he’s caught.

A sadistic trucker roams the highways in his mobile torture chamber, hunting for victims. Once they’re under his control, he brutalises and then kills them. But an illegally parked vehicle will prove his downfall…

In a quiet coastal community a brutal murderer stalks and kills at random. The police investigation will uncover a hidden world of sadomasochism, double identities and the most terrifying killer of all - a pitiless psychopath hiding in plain sight.

From the criminal underbelly of a rural town, a sadistic psychopath leaves a trail of destruction. As police discover a wave of vicious murders, investigators rush to track down the culprit. But this killer doesn’t fit any profile they’ve ever seen.

Police are stunned when they attend the scene of a multiple murder at the Alabama Institute for the Deaf and Blind. Five victims; all strangled within the space of twenty-four hours. So begins a manhunt to catch violent Serial Killer, Daniel Lee Siebert.

A rural Louisiana community is stunned when police begin to discover the corpses of young, seemingly fit and healthy men. Serial killer, Ronald Dominique stalks the bayous and canals around the town of Houma and it’s down to investigators to catch him.