Dr. Harold Shipman is suspected of killing more than 250 patients over 25 years and is therefor the most prolific serial killer in recorded history by proven murders. In britain he’s known as Dr. Death.
On 31 January 2000, a jury found him guilty of 15 murders. He was sentenced to life imprisonment and the judge recommended that he never be released.
Shipman died on 13 January 2004, after hanging himself in his cell.