LOUISVILLE, Ky. (WDRB) -- A man considered a person of interest in the murder of two Delphi teens is being brought back to Indiana from Colorado.

Police haven't formally connected Daniel Nations to the Feb. 2017 murders of Abby Williams and Libby German, but he gained national attention, when Indiana State Police traveled to interview him about the case.

Detectives say they have no information specifically including or excluding Nations as a suspect.

Last year, he was arrested in Colorado, where he was accused of threatening hikers on a trail with a hatchet.

Nations is being brought back to Indiana on an active warrant for failing to register as a sex offender in Johnson County.

What has gone before...

The bodies of 13-year-old Abby Williams and 14-year-old Libby German were found on Feb. 13, 2017, in a creek off a hiking trail in Delphi.

Days after the murders, local, state and federal authorities released a grainy cell phone image -- taken by Libby -- of a man they are calling a suspect in the case. They also released more information recorded by Libby's phone: audio of three words uttered by a voice authorities say belongs either to the man in the photograph, or another individual who was likely involved in the murders. The audio is barely more than a second long, and contains only one phrase. 

That phrase was, "Down the hill."

Authorities played the recording over and over again in a loop. It was also posted on the police Facebook page. They say they hope someone listening to the audio will recognize the voice -- and they are calling Libby a hero for recording it before she died.

Officials say they have other evidence in the form of both video and audio, but they are intentionally withholding it for the time being in an effort to verify the validity of any tips they receive.

It was a dramatic press conference last February, with officials pleading for information from the public -- at times getting emotional.

Indiana State Police Superintendent Douglas Carter said he was overwhelmed by the tragedy and evil of the case.

"Words tend to escape during these periods of times," he said. "I've only had a couple of other situations in my lifetime when I've been able to stand before you and say that. Why Libby? Why Abby? Why Delphi? Why Carroll County? Why the region? Why the state? Why even in the nation? I say that because this is a classic example -- a clear example -- that evil lives amongst us." 

"To the family of the community, the region, the state, as the leader of the Indiana State Police I say, I am so very sorry," he added.

Carter pointed to what he said was unprecedented time, manpower and resources being spent to solve the crimes -- resources that came from the local, state and federal levels.

"It's unlikely that any of you will ever see -- nor will we ever see or experience again -- the level of resources that is attached to this investigation," he said.

He pointed to the picture that had already been released.

"Someone knows who this individual is," he said. "Someone knows who this individual is. Is it a family member? Is it a neighbor? Is it an acquaintance? Is it an associate? Or maybe that one guy that lives over at that one place that's just kinda not right?"

"Maybe it's his jeans," he added. "Maybe it's his jacket or his sweatshirt. Maybe it's his shirttail. Maybe it's his posture. Maybe it's the right hand in his pocket."

"As poor as this picture is, somebody knows," he said.

And he had a message for the suspect:

"If you're watching, we'll find you."

He called on the public to be strong and recognize the importance of speaking out.

"Who's next?" he asked. "I hate to ask you that question. I'd give my life to not have to. But I know you've asked yourself that very question."

He asked the public not to get tired.

"We must keep our resolve for Libby and Abby. For this community. And frankly to ensure that good trumps evil -- and it will."

"We will stay committed -- with resolve very rarely exhibited with human behavior -- until this conclusion," he said. "Please be patient. Become our partners and communicate with us as often as you can."

He also said he had one last message for the deceased victims of the crime.

"And now from a very humble servant, that's the most blessed guy on this planet to represent the profession I represent, to Libby and Abby: It's my hope and my prayer that you're now experiencing God's promise of eternal peace."

Police are asking anyone who was parked at High Bridge Trail Head on February 13, 2017 between 1 p.m. and 5 p.m. to contact them. And if you can identify the man in the photo they released, please contact the Carroll County Sheriff's Department or the Delphi Police Department at 765-564-2345 or the Indiana State Police at 765-567-2125.  You can remain anonymous, if you request. 

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