American serial killer Gary Ridgway has been convicted of 48 murders. However, he stood twice as many. He murdered countless women and girls in Washington State. Most of the victims were prostitutes.

Peter Kürten, also called Vampire from Düsseldorf, was a multiple serial killer at the beginning of the last century. He committed a series of sexual crimes, robberies and murders of children and adults.

Pedro Alonso Lopez is a Colombian serial killer who raped and killed up to 300 girls in South America. He was called the monster by the Andes after leading the police to a mass grave of 53 girls in 1980.

Serial killer William Bonin killed at least 21 people in 13 months. He mostly dumped his victims on highways, hence the nickname The Freeway Killer.

American serial killer Dennis Rader, also known as BTK Killer (English for Bind, Torture and Kill), killed at least eight people in the period from 1974 to 1991.

"Kiss my ass.": Those were the last words of serial killer John Wayne Gacy. He was sentenced to death twelve times for 33 murders of young men and children - world record. The actual number of murder victims was taken to his grave by one of the most notorious serial killers of all time. He died from a lethal injection on May 10, 1994 at the Stateville Correction Center.

Yang Xinhai was born on July 29, 1968. As the son of a poor farming family, he was introverted and tenderly strung as the youngest child. At school he had to provide himself with food, which was always a challenge without money. When he was 17, he dropped out of school to join migrant workers.