(ABC NEWS) -- Police are looking into a possible connection between a kidnapping suspect and the unsolved murders of 13-year-old Abby Williams and 14-year-old Libby German in Delphi, Indiana.

Despite releasing photo and audio of a potential suspect, the killer has never been found.

Now, more than three years later investigators say they are looking into a person they believe might be connected to their murders.

Last week police arrested 42-year-old James Chadwell and charged him with the kidnapping and attempted murder of a 10-year-old girl - in Lafayette, about 20 miles from Delphi.

The sheriff said there were several factors leading them to look into Chadwell but declined to comment further.

Chadwell has pleaded not guilty to the charges against him and has not responded to requests for comment regarding a possible connection.

The murders of Abby and Libby have haunted the town of Delphi for years.

"I think about them all the time, their names are etched in my desk," said DOUG CARTER, Superintendent of the Indiana State Police.

In 2017, authorities released a grainy photo of a suspect they said was on the trail the same day the 8th graders went missing.

With no arrests, they later released video footage recovered from Libby's cell phone along with audio believed to be the suspect's voice.

Police believed Libby recorded it because she feared they were in danger.