A man photographed in a nature preserve where two teenage girls were found dead last week has been named a suspect in their apparent homicides.

Liberty German, 13, and Abigail Williams, 14, went on a hike last week at Delphi Historic Trails in Delphi, Indiana, on Monday, about 70 miles from Indianapolis. Their families were reported missing when they did not return as planned, and their bodies were found near an abandoned railroad bridge.

Police have for several days been trying to identify a man who was photographed walking at Delphi Historic Trails around the same time the girls would have been there. He has not yet contacted authorities, and has now been named a suspect in the double-homicide.

“He’s not just someone we want to talk to; we consider him a suspect in these murders,” Indiana State Police Sgt. Tony Slocum told CBS News. “We’re officially calling him a suspect versus a subject we’re looking to speak to. He’s going to be our main suspect at this time.”

The man’s refusal to contact police appears to be one among several reasons police have narrowed in on him.

“That doesn’t make him a suspect by not contacting us. It’s the totality of the evidence we’ve been developing so far that leads us to that,” Slocum said.

On Thursday, the FBI raided a home near the nature preserve, but the search did not yield anything of value to the investigation.

Anyone who can help identify the suspect or has any information is asked to call the Carroll County Sheriff’s Department at 765-564-2413, the Delphi Police Department at 765-564-2345 or the Indiana State Police at 765-567-2125. Anonymous tips are accepted.

Photo: Delphi Police Department