DELPHI, Ind. — The trial of a man accused of killing two teenage girls in a small Indiana community has passed its midway point following more than two weeks of testimony about the 2017 killings.

Prosecutors rested their case Thursday against Richard Allen after jurors heard recorded phone calls in which he told his wife that he killed Abigail Williams, 13, and Liberty German, 14.

Allen's trial began Oct. 18 at the Carroll County Courthouse in Delphi, the girls’ hometown. Jurors have been sequestered since the begining of the trial, which is scheduled to run through Nov. 15.

The defense began calling its first witnesses Thursday. A psychologist for the Indiana Department of Correction told jurors Friday that Allen was seriously mentally ill when he began confessing to the killings while housed at the Westville Correctional Facility.

Allen, 52, faces up to 130 years in prison if he is convicted on two counts of murder and two additional counts of murder while committing or attempting to commit kidnapping.

Here are some key moments in the trial so far:

Opening statements

Carroll County Prosecutor Nicholas McLeland opened the trial by telling jurors they would see and hear evidence, including incriminating statements Allen has made, that will convince them he forced the girls off a hiking trail into a secluded area while armed with a gun and cut their throats.

Allen was the person seen on cellphone video German recorded on the day the girls disappeared and an unspent bullet found between their bodies came from Allen's gun, McLeland said.

Defense attorney Andrew Baldwin told jurors Allen is innocent. Baldwin said the jury would hear witness statements and forensic evidence that would raise “reasonable doubt” that Allen is not the killer and said the state's timeline does not match the evidence in the case.

Someone else may have kidnapped the teens and returned them early the next day to the scene where they were found dead, Baldwin said.

Jurors see photos and video from the murder scene

In the first full week of the trial, jurors were shown photographs of the area where the teens' bodies were found in a wooded area off the hiking trail. The girls, known as Abby and Libby, had crossed an abandoned railroad trestle called the Monon High Bridge during their hike.

Some jurors and others in the courtroom gasped or turned away when gruesome images of their bloody bodies were shown, and the girls' mothers wept.

Jurors also viewed cellphone video that German recorded just before the youths vanished showing a man wearing a blue jacket and jeans following Williams as she crosses the Monon High Bridge.

In an enhanced version of the video shown to jurors, one of the girls says, “There’s no path so we have to go down here.” Just before the video ends, prosecutors said, the man seen in the video tells the teens, “ Down the hill .”

How Allen became a suspect

Investigators said in an affidavit released about a month after Allen's October 2022 arrest that he became a suspect after they went back and reviewed “prior tips” and found that he had been interviewed by an officer in 2017.

Trial testimony has revealed more details about how they zeroed in on the former pharmacy worker.

A retired state government worker who volunteered in March 2017 to help police with the investigation told jurors that in September 2022 she found paperwork that caught her eye.

Kathy Shank testified she found a “lead sheet” saying that two days after German and Williams’ bodies were found, a man contacted authorities and said he had been on the trail the afternoon the girls went missing. His name was listed incorrectly as Richard Allen Whiteman and marked “cleared,” Shank said.

She determined the man’s name was actually Richard Allen and recalled that a young girl had been on the trail at the same location and time and had seen a man.

“I thought there could be a correlation,” Shank testified, adding that she notified officers of her find.

What Allen told investigators in 2017

The girls' bodies were found Feb. 14, 2017, the day after they went missing.

Two days later, Allen contacted authorities and told them he was on the hiking trail the afternoon of Feb. 13, during the time period when the girls disappeared, according to testimony.

Dan Dulin, an Indiana Department of Natural Resources captain, told the court he spoke to Allen, who said he was on the hiking trail between 1 p.m. and 3:30 p.m. and remembered seeing three girls.

What Allen told investigators in 2022

After Shank brought Allen to investigators’ attention, they interviewed him in October 2022. Allen told investigators he arrived at the trail around noon and left no later than 2 p.m., not 3:30 p.m. as he told Dulin in 2017.

Steve Mullin, who was Delphi's police chief when the girls were killed and later became an investigator at the county prosecutor’s office, said Allen told him and another officer that he was wearing a blue or black Carhartt jacket, jeans and a beanie on the day the teens vanished.

Mullin said he asked Allen if he was the similarly dressed person seen in German’s cellphone video.

“His response was if the picture was taken with the girls’ camera, there was no way it was him,” Mullin testified.

Prosecutors also showed jurors police interviews with Allen videotaped before his arrest in which he repeatedly professed his innocence.

Allen's alleged confessions

On Thursday the jury heard several recorded phone calls of Allen speaking with his wife from prison in which he told her that he killed German and Williams. In one of the calls, he said, “I did it. I killed Abby and Libby.”

The jury heard testimony earlier from the former warden of the Westville Correctional Facility, where Allen was previously held, who said Allen claimed to have killed the girls with a box cutter that he later discarded.

Dr. Monica Wala, Allen’s prison psychologist during his time at Westville, testified Allen began confessing to killing the girls in early 2023 during his sessions with her. She said he provided details of the crime in some of the confessions, including telling her he slashed the girls’ throats and put tree branches over their bodies.

A report written by Wala and presented to the jury as an exhibit states Allen also told her he had planned to rape the teens but did not do so after he saw a van traveling nearby.

A state trooper testified Thursday that Allen's remark corroborated a statement by a man whose driveway passes under the Monon High Bridge and who said he was driving home in his van around that time.

Allen's attorneys have said their client made the incriminating statements while under the pressure and mental stress of being locked up and watched 24 hours a day and being taunted by people incarcerated with him.

During cross-examination, Wala acknowledged she followed Allen’s case with interest during her personal time even while she was treating him and that she was a fan of the true crime genre.

An unspent bullet and Allen's gun

Court documents released weeks after Allen’s arrest state that testing determined an unspent bullet found between the girls' bodies “had been cycled through” a pistol Allen owned.

Melissa Oberg, an Indiana State Police firearms expert, told the jury her analysis tied the round to Allen’s Sig Sauer, a .40-caliber handgun.

Allen’s attorney tried to cast doubt on the accuracy of firearms testing during cross-examination. Oberg said she is not aware of making any identification mistakes in her more than 17 years of analyzing firearms.