The unanswered questions consume us...

Their lives (and deaths) remain a mystery to this day.

Barbara and Patricia Grimes were murdered in 1956. New clues have raised hopes the killer might still be caught.

In 1908, Charles Luard found his wife Caroline shot dead at a neighbor's country house.

She hiked into the woods one winter afternoon and was never seen again.

He was one of the most prolific directors in Hollywood—until he was fatally shot by an unknown killer in his Westlake home.

She was only 16 years old when she was murdered and dumped in a cornfield.

In 1912, Little Bobby Dunbar went missing. Police found and returned a boy matching the missing child's description ... but was it really him?

What happened to the vanished heiress on that fateful evening in 1910?

Vicki Dill's older sister was murdered in 1973. After years of going unsolved, the case was finally closed ... and now the killer wants to be set free.

Their corpses were dressed in matching suits with homemade lead masks draped over their eyes...

One of these men might have committed one of the grisliest murders in American history.

Her screams went unanswered, and her murder remains a mystery.

On a summer night in Georgia, a killer crept into the DeFoor family homestead and slaughtered them with an axe.

There have been several Night Stalkers over the years . . . but few were as chilling as the first.

They vanished into thin air.

Police assumed a man missing for 30 years was dead ... until the victim had his "Aha!" moment.

In 1938, a young woman's bright future came to an abrupt and brutal end.

For 36 years Beverly England's killer has roamed free. Now police say they finally have a suspect in her murder.

Who was the man (or woman) behind history's grisliest unsolved murder?

A mother's love becomes the darkest evil.