The death of his mother triggered a change in the character of Peter Moore, who went on to kill four men in the space of three months.
Michael Ryan went on a killing spree in the small town of Hungerford, resulting in the murder of 16 people, including his own mother.
Peter Sutcliffe, a once quiet boy who was very close to his mother, was convicted of murdering thirteen women and attacking seven other women.
Thomas Watt Hamilton murdered almost an entire class of primary schoolchildren at the Dunblane Primary School in Scotland on March 13, 1996.
Experts study the case of Daniel Bartlam, who after weaving a soap opera excuse was found guilty of murdering his mother with a claw hammer.
Experts examine one of Britian's most shocking cases, Fred and Rosemary West, after the couple confessed to raping, torturing, murdering, and dismembering 12 young women including their daughters.
With a sunny exterior, Jed Allen's case shook the world when he killed his mother, stepfather, and six year old half-sister. Experts examine the dysfunctional family of the Wolverine.
Experts put Harold Shipman under the spotlight, as they examine one of UK's most disturbing criminal cases. They turn back the time to find out the motivation behind this mass murderer.
Known for his ghoulish nickname 'Frankenstein', experts study the case of Joachim Knychala.
Faced with charges of brutal murders and sexual assaults, experts study the mind behind serial child-killer, Robert Black.
Experts study the case of Leszek Pekalski, Poland's most notorious serial killer. The man's confession held him responsible for some of the most horrific cases of violence and rape.
Tragic Sandy Hook incident, where Adam Lanza killed his mother before shooting 20 children dead at the elementary school. Experts study the destructive relationship Adam had with his mother, and its effect on his behavior.
With claims of more than 100 victims over the span of three decades, experts study the case of Richard Kuklisnki, known as the 'Iceman'.