S6·E4 Hand Delivered

In 1995, police in San Diego, CA, are baffled by a pair of hands found in a dumpster. Through further investigation, they determine that the hands are those of missing person Don Hardin. With this knowledge, the police focus on local homeless man Dale Whitmer, whom had lived with Hardin around the time of his disappearance. However, they can find no solid, forensic evidence on Whitmer and the case goes cold. About a year later, investigators receive an anonymous letter with information about the crime that had been withheld from the press – information only the killer (or someone close to the killer) would know. Laser technology helps to identify the state, city, street address and even the office number from where the anonymous letter was mailed.