Washington: A 79-year-old man murdered at least 50 people, making him the most prolific serial killer in US history, the FBI said on Sunday. Samuel Little confessed to 93 homicides — mostly of women — between 1970 and 2005, the Federal Bureau of Investigation said. Although investigators have only confirmed his involvement in 50 of them, they believe all of Little's confessions are credible.

The FBI has set up a website showing his videotaped recollections of unidentified killings, alongside sketches — drawn by Little — of the 'victims'. "Many of his victims' deaths were originally ruled overdoses or attributed to accidental or undetermined causes," FBI said. He was jailed for life in 2014 after being convicted of three murders.