Professor Sir Alec John Jeffreys, FRS (born 9 January 1950 in Oxford, Oxfordshire, England) is a British geneticist, who developed techniques for DNA 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 on 26 November 1992.In 1994, he was knighted for services to science and technology.He received Copley Medal in 2014 for his pioneering work on variation and mutation in the human genome.