In Arlington, Texas, Michael Humphreys and Sandra Walton are brutally gunned down. Detectives don't know who the intended victim was but when they discover recordings of phone conversations with one of the victims, they get the break they need.

Robin Sowders is brutally beaten in his home in Bloomington, Indiana and later dies from his injuries. When his wife turns up at the police station, the investigation turns on its head. Only a wiretap will eventually reveal the truth.

Investigators must cast a wide net for clues when the family of Breckenridge resident Sharon Garrison report her missing. There's evidence to suggest she's skipped town, but a set of secret cassette tapes point to something more sinister.

Michelle Despinasse is shot inside her own home in Nanuet, New York. She is rushed to hospital but succumbs to her injuries. Investigators discover that in her final moments, Michelle made a secret recording that will reveal her killer's identity.

Melissa Atkin is found bound and murdered in her home in Smyrna, Tennessee. Eventually, the investigation focuses in on two individuals, with a series of recorded phone calls proving vital in exonerating one of them, whilst incriminating the other.

Elderly couple Roy and Angie Woodley are found brutally stabbed to death in their Fresno home. Initially believing the crime to be a robbery-gone-wrong, detectives soon realize the perpetrator may in fact be a family member with a grudge.

83 year old grandfather Jack Rains is brutually murdered at his home in Murfreesboro, Tennessee. When rumors emerge of an affair between the victim and a women half his age, police start to investigate his close friends.

Billy Staton and his fiance Leticia Castro vanish without a trace. Have they left town and eloped? The discovery of Billy's burnt out car and a shock confession, reveal a web of lies that only a secret recording can untangle