INDIANA, Pa. (AP) — Authorities say one of eight defendants has pleaded guilty but mentally ill in the slaying of a man taken from a western Pennsylvania home and later found stabbed in a rural area more than a year and a half ago.

Indiana County District Attorney Robert Manzi said Friday that 20-year-old Taylyn Edwards of Johnstown entered the plea to charges of first-degree murder and kidnapping in the October 2022 kidnapping and murder of 19-year-old Hayden Garreffa.

Trooper Cliff Greenfield told reporters at the time that Garreffa, who was autistic, was taken in a minivan from a relative’s Buffington Township home without his cellphone and medication, both of which “he never would have left behind.” His body was found two days later in Brush Valley Township with stab wounds and blunt force trauma.

Court documents list the case as adjudicated with a June 19 sentencing date. Edwards’ court-appointed attorney, Timothy Burns, told The (Johnstown) Tribune-Democrat that a mental health evaluation deemed his client competent “but with significant mental health impairment” at the time of the crime.

He said Edwards, who faces life without parole, would receive treatment during her incarceration, and “we thought this was the best resolution.”

Four men and two other women as well as a 14-year-old girl were also arrested in the case. The cases against the adults are still pending, with Manzi having predicted a “long and arduous prosecution” at the time of the arrests. The minor was charged as an adult, but her case was later transferred to juvenile court.

Investigators alleged that the slaying stemmed from an earlier dispute between the victim and one of the other defendants. Garreffa’s mother told The Tribune-Democrat after a January 2023 hearing that her son was severely autistic and was too trusting of people.