In "Serendipity," an episode from the fifth season of "Law & Order: Special Victims Unit," dermatologist Archibald Newlands takes a paternity test that proves negative. However, the sample happens to test positive against DNA evidence of a rape years before. After Newlands is murdered, an autopsy reveals that he planted a tube of another man's blood in his arm to fool the paternity test (but he didn't realize the blood belonged to a rapist).
Seem far-fetched? It is. But not very. In 1992, Dr. John Schneeberger, a physician living in Saskatchewan, drugged and raped Candace Foley. Foley, conscious throughout the ordeal, accused him and saved the clothes she had been wearing for evidence. But a blood test proved negative. Foley was persistent, but nothing came of it until years later, when John's wife figured out that he had been raping her teenage daughter from a previous marriage.
Candace's accusations were finally vindicated when John admitted that he had taken and saved blood samples from a patient to fool the DNA test. He had cut his arm open and planted a surgical tube filled with the blood inside [source: Dwyer].