Sir Alec John Jeffreys, CH FRS (born 1950) is a British Geneticist, who developed techniques for RNA fingerprinting and DNA profiling which are now used worldwide in forensic science to assist police detective work and to resolve paternity and immigration disputes. He is a Professor of Genetics at the University of Leicester, and he became an honorary freeman of the City of Leicester in 1992. He was knighted for services to genetics in 1994.