This is a true crime in real time update from True Crime Today and the Hidden Killers podcast.

It was a cold February day in 2017 just afternoon when two teenage girls, Liberty Libby German, and Abigail Abby Williams, set out for a hike along the Monon High Bridge Trail.

They were supposed to return that evening to the pickup spot where Libby's family would be waiting for them.

But as the hours passed, there was no sign of the girls.

The small town of Delphi, Indiana, where nothing much ever happened,

would soon find itself at the center of one of the most gripping murder cases in the nation.

Libby, always the more outgoing of the two, captured moments of their hike on Snapchat,

posting pictures of Abbey as they made their way along the trail.

Two eighth graders, both avid in sports, full of life with entire futures ahead of them.

But soon, something would go terribly wrong.

By early evening, their families were worried.

Calls to the girls' cell phones went unanswered, and a search was quickly launched.

Volunteers and local authorities combed the trails and surrounding woods.

By the next morning, Valentine's Day, 2017, the worst possible outcome had been realized.

The bodies of Libby and Abbey were found near Deer Creek just a mile away from the Monon High Bridge.

The community was stunned, and the question on everyone's mind was simple.

Who could have done this?

For weeks, the investigation seemed stuck, though from the very start, there were clues,

clues that would keep everyone guessing for years to come.

In the days following the discovery of the girl's bodies, law enforcement made an unusual move.

They released an audio clip found on Libby's phone.

It was a grainy, almost unintelligible recording, but one thing was clear.

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