In Little Falls, Minnesota, a retiree is disturbed by a home break-in, ending in a grim double murder. Audio recordings of the killings reveal what happened.
A mum in Georgia is killed after vanishing from home. Audio files captured by her tech-obsessed husband offer vital clues - and reveal a disturbing secret.
When a mother is shot dead next to her toddler, it sparks a murder investigation of passion, kidnapping and intimidation. Could a Dictaphone reveal her killer?
A mum accused of murder must clear her name by secretly recording a confession from the man she claims is framing her - and sordid revelations emerge.
In 1983, the Secret Service trails a counterfeiter. The audio recordings they find of him torturing women reveal one of history's most depraved serial killers.
A couple's fight reaches a tragic end when one of them is shot. A tape recorder that has captured the victim's final words becomes evidence in a murder trial.