Beyond Reasonable Doubt - Episode Guide

The hunt for the so-called Green River Killer, who murdered over 50 women, is the focus. Catching him took an advance in forensic microscopy to indisputably link minute paint particles from the victims' clothes to the killer.

The body of a murdered woman is found in a barrel along with an address book that has been soaked for over 30 years. Spectral imaging is used to recover the information from the address book, which gives the police the break they need.

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. The case goes cold until the groundbreaking 'Combined DNA Index System' finds a hit 5 years later, kicking off an epic hunt for the culprit.

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: the original investigation had searched for a male killer... but DNA reveals it wasn't a man, it was a woman.

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. The Agencies use every tool at their disposal – even NASA scientists – to help bring the bomber to justice.

In 1995, charred bones and a skull with five bullet holes were found inside a burnt antique trunk in the Nevada desert. Despite the full arsenal of cutting edge forensic tools at investigators' fingertips, it was a method first developed in the era of Sherlock Holmes that helped convict the killer.