A probable cause affidavit released this week surrounding the 2017 murders of two teenage girls in Delphi, Indiana, alleges suspect Richard Allen was tied to the killings after investigators found an unspent bullet at the crime scene that "had been cycled through" a pistol he owned.
Allen, 50, of Delphi, is now facing two counts of murder in the killings of Liberty German, 14, and Abigail Williams, 13, who were found dead in February that year near the Monon High Bridge Trail.
The affidavit filed by a state prosecutor says there was a ".40 caliber unspent round less than two feet away from Victim 2’s body, between Victim 1 and Victim 2’s bodies," which "had extraction marks on it."
On Oct. 13, following interviews with Allen, investigators executed a search warrant at his residence and found "jackets, boots, knives and firearms, including a Sig Sauer, Model P226, .40 caliber pistol with serial number U 625 627," the affidavit says.
DELPHI MURDERS: WHAT TO KNOW ABOUT THE KILLINGS OF LIBBY GERMAN AND ABBY WILLIAMS
Forensic analysis carried out by the Indiana State Police Laboratory on the pistol over the next week "determined the unspent round located within two feet of Victim 2’s body had been cycled through Richard Allen’s Sig Sauer Model P226," the affidavit alleges.
That weapon was purchased in 2001 by Allen, who, during a voluntary interview with the Indiana State Police on Oct. 26, "did not have an explanation of why the bullet was found between the bodies of Victim 1 and Victim 2," the document said.
"He again admitted that he was on the trail but denied knowing Victim 1 or Victim 2 and denied any involvement in their murders," it added.
The affidavit also alleges that Allen "stated that he never allowed anyone to use or borrow" the pistol and was spotted by a witness walking back to his vehicle following the killings, wearing clothes "that were muddy and bloody."
Authorities working the case first spoke with Allen in 2017, the affidavit says, but may not have returned to the interview until recently because of a "clerical error," according to Fox59.
The news station, citing an investigative source and The Murder Sheet true crime podcast, reported Thursday, "A civilian FBI employee mislabeled or misfiled tip information in the system, which means it didn’t show up in the correct location during a data search."
Fox News Digital has reached out to the FBI for further comment on the matter.
