A woman's dead body is found in a public park. When a knife through to be the murder weapon turned up, investigators had an opportunity which seldom occurs: to compare the microscopic marks on the weapon with the marks on the victim's body.

To learn more about how HLN protects listener privacy, visit cnn.com/privacy

Learn more about your ad choices. Visit podcastchoices.com/adchoices

Podden och tillhörande omslagsbild på den här sidan tillhör HLN. Innehållet i podden är skapat av HLN och inte av, eller tillsammans med, Poddtoppen.