25 most evil serial killers in history of the world – Their evil deeds will shock you (+Photos)

18 Peter Manuel

An American-born Scottish serial killer known to have killed 9 people across southern Scotland between 1956 and 1958, Manuel is suspected of having killed as many as 18 people. Police were unable to prove his guilt until his final murders, when some banknotes Manuel had been using to pay for drinks in Glasgow pubs were proven to be stolen from one of his victims. He confessed to these murders after his mother confronted him at the police station where he was being held. Manuel was hanged at Glasgow’s Barlinnie Prison for his crimes in July 1958. He was one of the last prisoners to be hanged in Scotland before they ended capital punishment.