MISSOULA, Mont. — A Montana man pleaded guilty Friday to stabbing two people to death, including a teenage girl, dismembering their bodies and then trying to dissolve them in tubs filled with acid in the basement of a home.

Augustus Standingrock Missoula County Jail

Augustus Standingrock's plea was part of a deal with prosecutors, who will recommend the 26-year-old be sentenced to life in prison with the possibility of parole. He pleaded guilty to deliberate homicide and accountability to deliberate homicide in the deaths last year of Marilyn Pickett, 15, and Jackson Wiles, 24.

Prosecutors have said Standingrock believed Wiles had sexually abused a young girl close to him.

The two were killed at the Missoula house of co-defendant Tiffanie Pierce, who still faces charges of deliberate homicide. She has pleaded not guilty and is scheduled for trial in March.

During Friday's court hearing, Standingrock told District Judge James Wheelis that he stabbed Wiles and that Pierce killed Pickett, the Missoulian newspaper reported.

The judge asked if Pickett had been free to escape the home. "She tried," Standingrock answered. He said he handed Pierce the knife and didn't stop her when she attacked the teen.

Pierce's roommate told police he was awakened by a woman's screams in August 2017, according to court records. He said he found Pierce and Standingrock in the bathroom washing off blood and that Pierce told him there was a dead woman in the basement.

Pierce later told her roommate that Standingrock brought over a couple of people and that he took them to the basement and attacked one while Pierce attacked the other, the roommate told investigators.

Standingrock and Pierce dismembered the bodies and tried to dissolve them in tubs filled with chemicals that she bought, prosecutors said. Officials said the coroner needed dental records and DNA to identify the bodies.

Investigators also found knives and an ax covered in blood and human tissue.

Standingrock had been scheduled for trial on Jan. 4. Missoula County Attorney Kirsten Pabst previously said she would not seek the death penalty.