Never-before-seen police tapes from inside the Sherri Papini case.

A workplace romance turns fatal for a Baton Rouge teacher-of-the-year mom. Could a three-year-old eyewitness help crack the case?

New details about the case of 17-year-old Brittanee Drexel, whose disappearance while on spring break stumped police for years.

An international search for a California man suspected in his wife's murder takes a shocking twist.

Video evidence leads police to learn the shocking identity of a former Arkansas senator’s killer.

The murders of three young girls in 1977 turned an Oklahoma community upside down after the case went cold for decades.

John Quiñones examines why investigators say an act of "divine intervention" helped them solve a Minnesota farmer's murder.

When a husband is violently murdered, his wife and her alleged lover become suspects.

A mysterious drug overdose kills new mom Christina Harris. Would she leave behind a crucial clue that actually points to a killer?

Police launch a 38-day nationwide manhunt to find a 15-year-old Tennessee student taken by her teacher.

An exclusive interview with a ‘fake doctor’ who hid a deadly secret.

Behind the glitz and glam of one of the sexiest shows in entertainment, an FBI investigation revealed Chippendales founder Steve Banerjee was the mastermind behind multiple murder-for-hire plots.

The investigation into a Texas murder reveals the killer may have been watching all along.

The latest reporting on the investigation, exclusive interviews and chilling new details in the Idaho case.

A hockey player, a brutal murder and a shocking witness – the victim’s young daughter.

Did a mom found dead in a luxury apartment slip and fall, or was it something more sinister?

Was it a case of self-defense or murder after a mom of two shot and killed her partner?

Affairs. Antifreeze. A letter from the grave. What really happened to Julie Jensen?

After a mother and daughter are murdered, investigators encounter a self-proclaimed vampire and taunting letters from a killer.

An Instagram model's relationship with an older man turns deadly, and a witness provides a shocking account of the fatal day.

Breaking coverage and exclusive analysis after a jury found former South Carolina attorney Alex Murdaugh guilty of murdering his wife and son.

A man wakes up to find his fiancée dead; a shocking confession changes everything.

How a North Dakota love triangle ended with murder and a house in flame.

A college student is murdered after being stalked. Did the University fail to protect her?

An open marriage, a secret affair, and a sinister plot for murder.

Investigating the remains of victims found on the bottom of Lake Mead, NV as the reservoir water level drops due to drought. So far, Thomas Erndt, Claude Russell Pensinger and Donald P. Smith have been identified, submerged for decades.

After a popular local musician is found dead, covert police surveillance uncovers horrific murders in Colorado and exposes a killer.

A twisted couple’s bizarre marriage pact, and how one of them was brought to justice by a small-town police chief.

A 19-year-old daughter vanished after a party and was never seen again. A new ‘ABC 20/20’ goes inside the stunning, decades-long investigation for justice for Kristin Smart.

The investigation of the Gilgo Beach murders, featuring interviews with family members of the victims and key players in the case - including Suffolk County Police Commissioner Rodney Harrison and Suffolk County Defense Attorney Ray Tierney.

After teen vanishes, family searches for answers but police see a suspect closer to home.

When a 12-year-old girl is snatched from her bedroom, the kidnapping shakes a small town.