1953 – James Watson and Francis Crick identify structure of DNA.
Watson and Crick pose with double helix
1984 – Alec Jefferys discovers Restriction Fragment Length Polymorphism (RFLP). RFLP breaks DNA into pieces and separates them using gel electrophoresis.
Injecting DNA into gel
1985 – UK police use first DNA profiling—a double murder investigation in a small Leicestershire town. Sir Alec Jeffreys concluded that a suspect held by police was not the attacker. However, in 1987, Jefferys conducted additional testing from a pool of 5,000 men and correctly identified the killer in the double murder. In 1988, the killer, Colin Pitchfork, was sentenced to life in prison.
1986 – Kary Mullins discovers Polymerase Chain Reaction (PCR), sort of a DNA copy machine used to replicate DNA. Mullis, a 1993 winner of the Nobel Prize in chemistry, had expressed an affinity to LSD and was subsequently removed as a witness in the original O.J. Simpson trial. The defense figured there was enough controversy in their case as it was.
1987 – Robert Melias is the first person convicted of a crime (rape) in the UK based on DNA evidence.
1987 – Tommy Lee Andrew is the first person convicted of a crime (rape) in the U.S. based on DNA evidence.
1988 – Timothy W. Spencer is the first person in the U.S. to be convicted and sentenced to death based on DNA evidence. Spencer was on probation and living in a halfway house when he raped and killed his victims.
Timothy W. Spencer
1989 – Gary Dodson is the first person in the U.S. to have a conviction overturned based on DNA.
1994 – Timothy W. Spencer, The Southside Strangler, is the first person executed in the U.S. because of a conviction based on DNA evidence.
1995 – The first DNA database begins operation in the UK.
1996 – Mitochondrial DNA is used in court for the first time. Mt DNA was compared and used in a trial to convict Paul Ware for the rape and murder of a child. DNA in a hair found on the body matched Ware’s DNA.
1998 – The FBI begins a national DNA database.