It is nearly impossible to imagine a criminal investigation that does not involve some kind of forensic science: firearms analysis, bloodstain patterns, arson, etc. But what leads us to trust these methods? Some point to the “CSI effect.” Viewers who have been watching true crime shows and trials for years have been trained to assume these methods lead to the right people getting arrested and convicted of some of the most heinous crimes. But what’s the science behind them? Are they valid?

In this podcast, host Molly Hermann lays out the lack of science behind some of the most well-known CSI tools, and tells the stories of the wrongfully convicted who went to prison for years. She interviews nearly 70 people - including forensic scientists, legal experts, and the exonerated - and digs into the larger issues within the criminal justice system that have let the “junk science” in.