Serial killers are people who murder three or more people.

Usually in a series of killings over a period of time, with a cooling-off period between each murder. Serial killers are often motivated by psychological gratification, thrill, power, or sexual satisfaction.

Some of the most famous serial killers in recent history are:

Ted Bundy: An American serial killer who murdered at least 30 women across several states in the 1970s. He was known for his charm, intelligence, and brutality. He often lured his victims by pretending to be injured or in need of help, then raped, strangled, and mutilated them. He sometimes revisited the crime scenes and engaged in necrophilia with the corpses. He was executed by electric chair in 1989.
Jack the Ripper: A notorious and unidentified serial killer who terrorized London in 1888. He killed at least five women, mostly prostitutes, by slashing their throats and abdomens. He also sent taunting letters to the police and the media, some of which contained organs from his victims. He was never caught or identified.
Ed Gein: An American serial killer who murdered two women and exhumed several corpses from local graveyards in Wisconsin in the 1950s. He was obsessed with his domineering mother and wanted to create a “woman suit” out of human skin. He also made furniture, clothing, and masks from human bones and flesh. He was arrested in 1957 and died in a mental hospital in 1984. He inspired the characters of Norman Bates in Psycho, Leatherface in The Texas Chainsaw Massacre, and Buffalo Bill in The Silence of the Lambs.
John Wayne Gacy: An American serial killer who murdered 33 young men and boys in Illinois between 1972 and 1978. He was a successful businessman and community volunteer who also performed as a clown at children’s parties. He lured his victims to his home, where he sexually assaulted, tortured, and strangled them. He buried 26 of them in the crawl space under his house, three others elsewhere on his property, and four in a nearby river. He was executed by lethal injection in 1994.
Carl Panzram: An American serial killer who confessed to killing 21 people and raping over 1,000 men and boys across several countries in the early 20th century. He was a career criminal who spent most of his life in prison, where he continued to commit violent acts against inmates and guards. He also claimed to have set fire to buildings, and robbed trains, ships, and banks, He was hanged in 1930 after killing a prison employee.
Jeffrey Dahmer: An American serial killer who murdered 17 men and boys in Wisconsin and Ohio between 1978 and 1991. He was a necrophile and a cannibal who dismembered his victims and kept their body parts as trophies or food. He also attempted to create “zombies” out of some of his victims by injecting acid or boiling water into their brains. He was arrested in 1991 after a victim escaped from his apartment. He was beaten to death by a fellow inmate in 1994.
Aileen Wuornos: An American serial killer who killed seven men in Florida between 1989 and 1990. She was a prostitute who claimed that she acted in self-defense after being raped or assaulted by her clients. She was convicted of six murders and executed by lethal injection in 2002. She was portrayed by Charlize Theron in the film Monster.