English detectives team up with a pioneering scientist to solve a case of sexual assault and serial murder. In 1983, a quiet country village in Leicestershire County, England is gripped with fear as authorities search for the killer of 15-year-old Lynda Mann. Clueless, they start again when Dawn Ashworth is killed three years later. They enlist the help of Dr. Alec Jeffreys, a molecular biologist who uses his breakthrough technique of genetic fingerprinting to rule out one suspect by comparing his DNA with that of semen found on the victims' bodies. Police set up a DNA dragnet to trap and convict the real killer, but are stymied when Richard Buckland confesses to the crime and his DNA does not match. Later, it is discovered that the true killer, Colin Pitchfork, had avoided giving a DNA sample during the dragnet and this brings the focus on him. This 1986 murder case is the first to use DNA as evidence in a criminal case.
