Bad Blood

Bad Blood refers to episode 18 of the Season 6 of the television series Forensic Files which was broadcast for the first time on September 17, 2001.

Plot summary
In 1992, in Kipling, Saskatchewan, Dr. John Schneeberger is accused of sedating and sexually assaulting one of his female patients and his step-daughter. DNA tests demonstrate that the doctor is innocent, but the female patient still insists that he sedated and raped her.

On three occasions, blood was taken from the doctor's arm for DNA testing, and each time, the results exonerated Schneeberger. Seven years later, a private investigator takes lip balm from Schneeberger's car and has it DNA-tested, and the results were a match to the perpetrator. So, how did Schneeberger trick earlier investigators?