Surveillance Footage Shows Mystery Man Who May Help Cops Shed Light on Murder of Teen Hikers

The image of a man walking along a hiking trail close to where a 13-year-old girl and her friend were found murdered has been released by police investigating the horrific crime.

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The photo of the mystery man came as an eerie image of Abigail Williams, 13, was released.  It was posted to Snapchat by Liberty German, 14, just before the two girls vanished while on a hike Monday.

German took another haunting photo of a lonely trail ahead. She could not have imagined a killer was lurking nearby.

The bodies of the two girls were discovered just a few feet from a creek Tuesday. Police have classified their deaths as a homicide.

Surveillance photos of a man police are looking for, seen on that same trail around the time the girls vanished, has been released.

Police have not named the mystery man as a suspect but would like to speak to him about what he may have seen. 

Carroll County Sheriff Tobe Leazenby said during a press conference Thursday that authorities do not have any suspects.

"We are asking help from the public to help identify him so he can be contacted regarding what he might have seen," police said in a statement.

Read: Etan Patz's Dad is 'Truly Relieved' After Man is Convicted of Murdering His Son, Who Vanished in 1979

Killers have been known to stalk isolated hiking trails, according to safety expert Steve Kardian.

"Don’t go into the woods, don’t go hiking, don’t go into a place of isolation without a weapon," he told Inside Edition. 

He said that if someone approaches you in the woods and tries to attack, use your elbows and knees to fight back. He also recommended using your backpack as a weapon.

Watch: 1 Hiker Dead, 4 Others Injured After Plunging Down Icy Mountain