Libby and her best friend Abby Williams, 13, were on a local Delphi hiking trail when they were killed on Feb. 13, 2017. No arrests have been made and no suspects have been named.
Indiana State Police said that, while investigating the case in December 2021, they "uncovered" a fake Snapchat and Instagram profile called "anthony_shots," where the unknown user misappropriated photos of a known male model for his own profile image and communicated with underage girls "to solicit nude images, obtain their addresses, and attempt to meet them."
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The user of the "anthony_shots" profile, which was active in 2016 and 2017, "portrayed himself as being extremely wealthy and owning numerous sports cars," police said.
The male model in the photos has been identified and isn't a person of interest, according to police.
New information on the "anthony_shots" account is now public thanks to the true crime podcast Murder Sheet, which obtained a transcript of a police interview with 27-year-old Kegan Kline, an Indiana man arrested in 2020 and charged with possession of child pornography and related charges.
LISTEN: Police release audio of Delphi, Ind. murder suspect
Murder Sheet found the transcript while looking through documents associated with Kline's criminal case online; this interview transcript was mistakenly published online and later taken down.
According to the published transcript, in Kline's interview with police in 2020, he admitted to using the "anthony_shots" profile on social media and admitted to talking to Libby.
Police said Kline's device logged into the "anthony_shots" Snapchat account the day that the girls were killed. Police also accused Kline of communicating with Libby on the day she was killed, according to the transcript.
SEE MORE: Delphi murders: Police seek information on fake social media profile that may be linked to killings
Kline, in the interview, repeatedly denied killing Abby and Libby, according to the transcripts. He has never been charged with the crime.
Kline described it as "coincidence that I happened to talk to her," according to the transcript.
At one point, Kline told police of Libby, "I don't remember talking to her really. I didn't even know who she really was until after I saw that on the news."
Police said the "anthony_shots" account told someone online about Libby: "I was supposed to meet that girl, but she never showed up." But Kline said in the interview he never would have met with Libby in person.
Police, according to the transcript, also said Kline failed a polygraph and then deleted his Snapchat and Instagram accounts and searched online "how long does DNA last."
When police asked why he searched that, Kline responded, "I have no clue. I don't know. Because probably because they DNA tested me."
Asked why he'd worry about his DNA in this case, Kline responded, "I wouldn't. ... That's just a common thing to freak out about."
Kline's lawyer has not responded to ABC News' requests for comment.
Kline pleaded not guilty to the possession of child pornography and related charges. He's next due in court on April 14 for a pretrial conference.
One of the co-hosts of the Murder Sheet podcast, attorney Kevin Greenlee, told ABC News that another part of the police transcript that stood out to him was how "police reveal that, in studying the messages sent from the 'anthony_shots' account, they see differences in languages and phrasing choices that make it apparent to them that at least two different people were accessing that account and using it to send messages to underage girls."
Greenlee told ABC News, "At one point in the interrogation, the police officer ... tells Kegan Kline, 'We do not believe you are the one that committed these murders.' But then they point out that Kegan Kline had taken a polygraph test where he was asked: 'Do you know who committed these murders?' And the police say he failed that exam. So what does Kegan Kline know?"
Indiana State Police will not confirm that Abby or Libby communicated with "anthony_shots." The head of the Indiana State Police, Doug Carter, has been tight-lipped on the "anthony_shots" investigation, telling ABC News last month that the profile has "generated a tremendous number of leads for us -- and that's as far as I can go."
"We are aware 'The Murder Sheet' has released a transcript," state police said in a statement to ABC News Tuesday. "The information that was released did not come from the Indiana State Police nor The Delphi Double Homicide Task Force. This is still an ongoing investigation."
The "anthony_shots" account isn't the only possible lead in the Delphi case; police also have photos, video and audio.
In 2017, authorities released a grainy image of the suspect, who they say was on the trail the day the girls went missing. In 2019, police released a brief video clip -- footage taken from Libby's phone -- showing a grainy image of the suspect walking on the bridge near where the girls were last seen.
Police also publicized what they say is the suspect's voice -- a recording of him saying "guys ... down the hill" -- which was recovered from Libby's phone.
Authorities in 2019 released a new suspect sketch that officials said was based on a witness' recollection of what he or she saw.
Anyone with information can submit a tip at email@example.com or 765-822-3535.
ABC News' Jenn Leong and Matt Knox contributed to this report.