LOUISVILLE, Ky. (WDRB) -- It has been more than five years since Abby Williams, 13, and Liberty "Libby" German, 14, were murdered in Delphi, Indiana, and an arrest in the case has yet to be made.

New developments were released Wednesday in the murder mystery of the two girls, who went for a hike on Valentine's Day in 2017 on the popular Monon High Bridge Trail in Delphi when they went missing. Their bodies were found the next day.

In an interview with Fox News that aired Tuesday, Libby's grandma, Becky Patty, said police have DNA in the case.

Libby used her own cellphone to capture the image and voice of her suspected killer saying "down the hill."

"This young lady's a hero. There's no doubt," Indiana State Police Sgt. Tony Slocum said at the time. "To have enough presence of mind to activate the video system on her cellphone to record what we believe is criminal behavior that is about to occur."

Last year, police announced what seemed like a real bombshell in the case: a fake social media account, "Anthony_Shots," had been communicating with Libby. The profile showed photos of a young male model, but authorities said the account actually belonged to 27-year-old Kegan Anthony Kline of Peru, Indiana. 

Kline, who is currently in jail on child porn charges, failed a polygraph when he was asked questions about the deaths of the girls.

According to a Fox News report, a police document was accidentally posted online revealing disturbing details about Kline. He allegedly told investigators he used the social media account to communicate with Libby the day she was killed. He also allegedly used his computer to search "how long does DNA last?"

Kline has not been charged with the girls' murder and has denied any involvement in the crime.

"It was a real shock, because then I had to face the fact that I didn't monitor her phone or social media enough," Patty said.

The new interview with Patty and confirmation from Libby's family show what detectives with ISP are working with. While police haven't said how the girls were murdered, Patty confirmed an important detail.

"Police have said there (is) DNA," she said. "They have made the comment that there was DNA. I know for a fact that this Anthony Shots account did have contact with Libby. I feel that he knows more than he says."

Kelsi German, Libby's sister, was the last person to see the girls alive when she dropped them off at the hiking trail on that day in 2017. For her, the last image of her sister — carefree and smiling — is forever frozen in time.

"I remember us just being so happy in the car and listening to Twenty One Pilots, and the windows were open, and it was just so warm," German said. "And she got out of the car and told me she loved me."

The families of both girls and state police are asking the public to look at the image of the suspected killer and listen to the voice captured on Libby's phone in the hopes that someone, somewhere will recognize it and call ISP or the FBI.

To watch Patty's interview with Fox News, click here.

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Copyright 2022 WDRB Media. All Rights Reserved. Fox News also contributed to this report.