After the deaths of murderers Ian Brady and Myra Hindley, news breaks that a briefcase left with Brady's lawyer may contain clues to his motives.

Successful real estate agent Todd Kohlhepp hides a deeply disturbing life -- one in which he kidnaps, enslaves and kills.

While working as a nurse for the elderly, Elizabeth Wettlaufer makes it her mission to kill the very people she's supposed to care for.

After serving a sentence for killing his wife, Theodore Johnson is released from prison -- only to keep on killing.

Before committing suicide, serial killer Richard Dorrough leaves a note in which he confesses to three murders. But did he actually kill more?

The case of Eddie Leonski, a US soldier based in Australia compelled to strangle numerous women when he became obsessed with the idea of `stealing' their voices.

The crimes of Angus Robertson Sinclair, who raped and murdered Helen Scott and Christine Eadie and dumped their bodies six miles apart in East Lothian in October 1977. He became the first person in Scotland to be retried for the same crime after an acquittal, following a change in the double jeopardy law. He is suspected of murdering up to six other women.

Explore what drove female UK serial killer Joanna Dennehy to take the lives of three men, who may have done nothing more than look at her in the wrong manner.

The case of Israel Keyes, who admitted to being a rapist, arsonist, burglar, bank robber and serial killer. Keyes saw the United States as a hunting ground for killing and other criminal activities, often planning his murders years in advance, burying murder kits underground to aid in his killings. He committed suicide while awaiting trial for the murder of Samantha Koenig.

In 1990, a man named Douglas Perry kills three women. By the time authorities track Perry down, more than two decades later, Douglas has become Donna.

The case of Mark Erin Rust, who became obsessed with murdering women and keeping a trophy after each kill. With expert analysis from Dr Linda Papadopolous.

For 30 years, Ireland's Kieran Kelly targets homeless people and transients, sometimes even pushing them into oncoming trains.

French serial killer Michel Fourniret, who confessed to kidnapping, raping and murdering nine girls over a span of 14 years from the 1980s to the 2000s. His wife, Monique Olivier, exposed him after hearing the news of another child murderer's wife being convicted.

The crimes of Surender Koli, who killed numerous people before eating his victims' body parts. Featuring an exclusive interview with the psychologist who spent hours assessing the so-called Slumdog Cannibal.

The murders of three women with a crossbow. Stephen Griffiths paraded the weapon he had used to kill Bradford sex workers Susan Rushworth, Shelley Armitage and Suzanne Blamires during 2009 and 2010.

The case of Anders Behring Breivik, who claimed he was compelled to murder 77 people and injure a further 241 on a pre-planned killing spree in downtown Oslo and Utoya Island in July 2011.

American killer Anthony Sowell, who murdered 11 people between May 2007 and September 2009, during which time he was dubbed the Cleveland Strangler.

Sheila Labarre invites men to her New Hampshire farm, where she abuses and murders them, leaving behind grieving families.

A young man enters a police station, complaining of harassment from a neighboring town's police force. Later, that same man would confess to murder.

Watch Anthony Shore. Episode 1 of Season 2. 1. Anthony Shore 44m In 1986, Anthony Shore, a married father of two, abducts and murders a 14-year-old girl. It would be the first in a string of brutal killings.