Podcast: How DNA brought the Potomac River Rapist cold case to trial

We revisit the case of Giles Warrick — known as the Potomac River Rapist — who is charged with killing a 28-year-old intern Christine Mirzayan in 1998. He’s also a suspect in six other rapes in Montgomery County. A judge is expected to make a decision Wednesday on whether a key piece of DNA evidence linking him to the murder can be introduced during his trial. We speak with reporter Paul Wagner who is releasing a podcast about the crime called ‘Unknown Subject.’