In 1982, the first victims of America’s most prolific serial killer were found. The killer was at large for two decades, amassing a body count of over 50 women. Catching him took an advance in forensic microscopy.

In 1999, detectives investigate the body of a murdered woman found in a barrel with an address book that had been soaked over 30 years. Using spectral imaging, scientists recover the information from the address book.

In 2002, armed with DNA and a license plate from a particularly violent rape case, a detective thinks he has an easy case to crack. But neither provides a match until the Combined DNA Index System finds a hit 5 years later.

In 1986, the LAPD arrive at a murder scene. They’re certain it’s an open and shut case but the case quickly goes cold. It takes 20 years, and the advent of DNA testing to provide a stunning new lead.

In 1996, a bomb goes off at the Atlanta Olympics killing one and leaving hundreds injured. After a further 5 bombs are detonated, the FBI, ATF and GBI realize they're dealing with a serial bomber.

In 1995, charred bones and a skull with bullet holes were found inside a trunk in the Nevada desert. Despite the cutting edge forensic tools available, it was a method developed in the era of Sherlock Holmes that helped convict the killer.