Jury selection begins Monday in the long-awaited trial of a Delphi, Indiana, man accused of killing two teenage girls while they hiked on a local trail in broad daylight in 2017.
The case garnered national intrigue, and remained a mystery for over five years until suspect Richard Allen was arrested in October 2022. He's pleaded not guilty to murder charges.
Here’s everything you need to know about the case.
The murders
On Feb. 13, 2017, best friends Abby Williams, 13, and Libby German, 14, were enjoying a day off from school in their hometown of Delphi, a quiet, small town of nearly 3,000 residents in central Indiana.
They were on a hiking trail, walking, chatting and snapping photos, when they disappeared.
Their bodies were found the next day.
Abby, who was raised by her single mother, hoped to pursue a career in forensic science.
Libby, a gifted athlete raised by her grandparents, wanted to work with the FBI and solve crimes.
Police have never released how the eighth graders were killed.
According to video recovered from one of the victim's phones, Abby or Libby mentioned "gun" as a man approached them, and a .40-caliber unspent round was found less than 2 feet away from one of the bodies, according to a probable cause affidavit. But court documents also mention the involvement of a knife in the killings.
'Down the hill'
In the aftermath of the shocking double slayings, authorities released a clip of the suspect's voice -- a recording of him saying "down the hill" -- which was recovered from Libby's phone.
According to the probable cause affidavit, a man was seen and heard telling the girls, "Guys, down the hill," and Abby and Libby then went down the hill.
Authorities also released a grainy image of the suspect, who they say was on the trail the day the girls went missing. State police later circulated a brief video clip recovered from Libby's phone that showed the suspect walking on the bridge near where the girls were last seen.
The arrest
For more than five years, the case remained unsolved, haunting Delphi residents.
Police released disparate sketches of possible suspects, and authorities announced that, while investigating the case, they "uncovered" a fake Snapchat and Instagram profile called "anthony_shots," where the user used photos of a male model and communicated with underage girls in an attempt to meet them. The man suspected to be behind the "anthony_shots" account was later identified and not linked to Abby and Libby's murders.
No suspect was named in the murders until Allen was arrested in October 2022.
Community members were shocked to learn that the suspect was a 50-year-old husband, father and Delphi resident who worked at the local CVS.
"How can somebody do that and then just go on living life like nothing happened?" Libby's grandfather, Mike Patty, told ABC News hours after the arrest was announced.
Allen admitted to police that he was on the trail that day, but he denied any involvement in the murders, according to court documents.
Police analysis of Allen's gun determined that the unspent round discovered within 2 feet of one of the victims "had been cycled through Richard M. Allen's Sig Sauer Model P226," the probable cause affidavit said.
"When asked about the unspent bullet, [Allen] did not have an explanation of why the bullet was found between" the girls' bodies, the probable cause affidavit said.
When Allen voluntarily spoke to police on Oct. 26, 2022, he said he never allowed anyone to borrow that gun, which he said he owned since 2001, the document added.
Video from Libby's phone showed a man wearing a dark jacket and jeans on the trail. In an October 2022 interview, Allen told investigators that he wore jeans and a blue or black Carhartt jacket that day on the trail, and Allen's wife confirmed to police that he owns a blue Carhartt jacket, according to the probable cause affidavit.
Investigators believe Allen is the grainy suspect seen on Libby’s cellphone video. Investigators also claim he forced Abby and Libby down the hill to the spot where they were killed, according to the probable cause affidavit.
Investigators believe Allen was seen walking back to his car with "clothes that were muddy and bloody," according to the probable cause affidavit.
Allen allegedly confessed to the killings several times in a jail phone call with his wife in April 2023, according to unsealed court documents.
"Soon after" that call with his wife, Allen's attorneys filed an emergency motion saying his mental state had declined and he should be moved, alleging Westville Correctional Facility was unfit, the document said. He was evaluated by two psychiatrists and a psychologist who determined he didn't need involuntary medication and didn't need to be moved, according to the document.
The trial
The trial will be held at Delphi's Carroll County courthouse. But jurors will be selected from residents of Allen County, which is over 100 miles away and encompasses Fort Wayne, Allen County Judge Frances Gull ruled last year.
Jury selection begins Monday in Fort Wayne, and once the jury is selected, the case will move to Delphi.
Gull said it makes sense to keep the trial in Carroll County, where witnesses and families live, saying the expense to move the proceedings would be "extraordinary."
But she added, "It's painfully clear that it would be impossible to find a jury in Carroll County not involved in this case."