Dr. Harold Fredrick Shipman was convicted of murdering 15 elderly women by injecting them with lethal doses of diamorphine. Further investigations revealed he had killed over 400 people in various locations in England, demonstrating his actions as a typical serial killer who murders 3 or more people over a period of one month or longer. Serial killers commonly exhibit traits like a history of childhood abuse, interest in torturing animals, and involvement in petty crimes.