Mari Gilbert became an advocate for murder victims after her daughter Shannan's disappearance led to the discovery of the Gilgo Beach Murders — then Mari was killed herself by her other daughter Sarra.

On June 12, 1994, Nicole Brown Simpson was murdered at her Los Angeles home — and her ex-husband O.J. Simpson soon became the prime suspect.

Authorities believe that Naya Rivera used the last of her energy to push her four-year-old son Josey to safety on their boat before disappearing beneath the surface of California's Lake Piru on July 8, 2020.

A friend of Nicole Brown Simpson who fatefully visited her Brentwood home on the day of her murder, Ron Goldman is one of the most famous innocent bystanders in modern history.

On December 15, 2017, billionaire couple Barry and Honey Sherman were found murdered in their Toronto home — and no one knows who killed them.

On August 2, 2006, a lawyer named Robert Wone was assaulted and murdered while staying with friends in Washington, D.C. — and while his friends were charged with tampering with the crime scene, his killer has never been caught.

In 2014, YouTuber Kenny Veach set out to explore a mysterious M-shaped cave he had discovered near Nevada's Nellis Air Force Base in the Mojave Desert — then mysteriously vanished, never to be seen again.

A convicted pedophile who lived near JonBenét Ramsey at the time of her 1996 killing, Gary Oliva had a deep obsession with the six-year-old pageant star — and claimed responsibility for her murder in a series of prison letters.

In 2010, paroled killer Gregory Green married Faith Harris, the daughter of the pastor who’d advocated for his release. Years later, he murdered all four of her children in a fit of rage.

In May 1998, aspiring actress Brynn Hartman shot and killed her husband — then turned the gun on herself.

Although Dick Turpin's exploits were later romanticized in plays and serial fiction, in reality, he was a ruthless criminal who terrorized England in the early 18th century.