The poisoning of Urooj Khan
In 2012, Urooj Khan won a million dollars with a lottery a ticket he purchased at a 7-Eleven near his home in Chicago. But before he had a chance to collect his winnings, he died. It was presumed the 46-year-old had died of natural causes – until the medical examiner discovered that Khan had been poisoned with cyanide. But no one has ever been able to connect the poisoning and anyone with a motive. The case remains unsolved.
John Schneeberger’s bad blood
For years, a female patient claimed that John Schneeberger, a physician in Saskatchewan, Canada, had drugged and raped her in 1992. But repeated DNA tests failed to match the sperm sample from her underwear. The patient hired a private eye to obtain DNA samples from Schneeberger’s car – which proved to be a match. Investigators brought Schneeberger back in for more extensive tests and were finally able to get a match and reach a conviction (he was also convicted of drugging and raping his step-daughter). At trial, Schneeberger revealed how he had been able to fool the DNA exam: He had implanted a vial of another man’s blood in his bicep and tricked the nurse into drawing blood from that vial.
The Zodiac Killer
The Zodiac Killer murdered a number of people in the San Francisco Bay area in the 1960s and early 1970s and has never been caught – but not for lack of forensic evidence. Zodiac, as he called himself, left behind fingerprints and handprints at his crime scenes and on the taunting letters he sent to law enforcement. The text of the letters, themselves provided forensic evidence as well. And while several people have claimed to be the Zodiac, they don’t match the forensic evidence from the killings.