DELPHI, Ind. — A pattern on the body of Delphi, Indiana, murder victim Libby German showed her blood was mixed with moisture, an officer testified at Richard Allen’s trial. The officer said he believed the wetness was Libby’s tears — prompting family members watching his courtroom testimony to audibly react.

Libby, 14, and her best friend, Abby Williams, 13, were walking along a hiking trail in rural Delphi when their throats were slit and they were left in the woods on February 13, 2017. Their bodies were found the next day.

Allen was arrested in 2022 and pleaded not guilty to murder.

Major Pat Cicero of the LaPorte Sheriff’s Department took the stand Monday. Cicero was not at the crime scene in 2017, but said he studied crime scene photos and various reports.

Abby’s mother wept quietly in the courtroom as prosecutors showed close-up photos of the girls’ faces, bodies, hands, legs and feet.

Cicero showed the jury a picture of a bloodstain on a tree. He explained that it was a transfer stain, meaning it was left behind when a bloody object touched it.

Cicero testified that the blood stains and patterns on the tree led him to believe that the attack on Libby began at the tree, with gunshots that could cause the tree to splatter.

Libby died from her injuries in a large pool of blood while leaning against the tree, Cicero said. He said he believed she was then dragged about 20 feet to where her body was found.

Abby was likely restrained or unconscious when she was killed, Cicero said, because she had no blood on her hands or arms and was found with her hands raised vertically.

“Her final position is almost like she’s boxing,” he said.

Cicero said he has been to hundreds of crime scenes and described the position of Abby’s body as highly unusual. “I never saw him,” he said.

He also said that Abby probably didn’t die right away. “This would have taken some time,” he said.

Allen has admitted to being on the hiking trail the day the girls were killed, but denies any involvement in the killings.

On Monday, Indiana State Police Forensic Investigator Stacy Bozinovski said no DNA linked Allen to the crime scene in Delphi, Indiana.

RELATED | Delphi murders trial: Extended video from victim’s phone played in court

The court continues on Tuesday, October 29.

ABC News’ Janel Klein contributed to this report.