According to the link below it could be Pedro Alonso López, known as the Monster of Andes killed up to 300 young girls in the 1990s.
And then there's GP Harold Shipman, from the UK who could possibly have killed up to 250 people.
Luis Alfredo Garavito of Columbia in the 90's. He was have said to have killed anywhere between 172-400 people. Proven number of victims was 138. Goggle him.
God. If you are gullible enough to believe the bible he wiped out most of mankind in the great flood. Makes our attempts at murder seem fairly lame.
