Andries Tommy Williams (born 1970), known as The City Serial Killer, is a South African serial killer who, between 1987 and 2008, strangled to death three acquaintances, two of them children. Labeled as the country's longest-active serial offender, Williams was found guilty of all three murders in 2009, and sentenced to two life imprisonment terms plus 10 years for his first murder, which was committed while he was still a minor.