A facial recognition expert is also discussing the killer's appearance.
Potential new clues are emerging in the hunt for the killer of two teenage girls in Indiana.
The clues come following the grainy image of the suspect which was recorded by 14-year-old Liberty German on her cell phone before she was murdered along with her best friend, 13-year-old Abigail Williams.
She also captured haunting audio of their killer's voice, saying, "Down the hill. Down the hill."
But there is concern that the still image of the suspect cannot be digitally enhanced to get a clearer picture of his face, facial recognition expert Tom Joyce told Inside Edition.
"The investigators will still go over the image in quite detail to identify shoe type, shoe brand, the jeans, pants, the jacket, any logos, any brand," he said. "And the surrounding areas if there is anything in that image that might generate itself or present itself for the investigation."
Veteran New York Homicide Detective Sergeant Joe Giacalone has studied the photo and determined the suspect is about six feet tall and weighs between 190-210 pounds.
“He's got a lot of brown hair, it looks like," Giacalone told Inside Edition. "He may even have a mullet. You can see over on the side here. He might have a goatee or a beard and mustache. He's got that thick blue jacket on and blue jeans and his brown walking boots or trail boots."
There also appears to be a bulge in the suspect's right hand jacket pocket where he may have been hiding some kind of weapon.
"I think he's armed with a weapon because he is able to control two people and it's very difficult to control two people without a weapon," Giacalone said.
In addition, could there be a tantalizing clue in the poignant last photograph taken of Abigail Williams by Liberty German? In the distance, a shadowy figure that may be the suspect can be seen.
Investigators are still combing through wooded areas around the trails in Indiana looking for any clues that could lead them to the girls' killer.
The general public is also doing their part, with nearly 4,000 calls and emails to the national tip line.