ALBUQUERQUE, N.M. — A New Mexico teenager pleaded guilty in the shooting deaths of his parents and three young siblings on Friday, more than two years after authorities say he opened fire at his family’s rural home south of Albuquerque.  

Nehemiah Griego entered the guilty pleas during a hearing in state children’s court to two counts of second-degree murder in the deaths of his parents and three counts of child abuse resulting in death in the slayings of his three younger siblings — Zephaniah, Jael and Angelina. He was 15 at the time of the January 2013 shooting.

The brief hearing ended more than two and a half years of litigation as Griego received extensive treament from the state, said Griego’s attorney Jeffrey Buckels. A hearing will be held in January to decide whether Griego, who is now 18, will be sentenced as a juvenile or an adult.

“The parties believe that this agreement is the best resolution for Mr. Griego and the State, as well as for the victim’s family, which was fully apprised of the agreement in advance of (the) plea hearing,” Buckels said in a statement.

Griego’s sentencing terms could range from probation to three life sentences plus 30 years if he is sentenced as an adult, Buckels said. Griego’s family members did not immediately respond to a request for comment.

After the 2013 killings, authorities alleged that Griego reloaded his parents’ two semi-automatic rifles and put them in the family van and planned to gun down Wal-Mart shoppers, though investigators had no information that Griego actually went to a Wal-Mart the day of the shooting.

A security official said that after the shooting, Griego spent much of the day at his church, wandering the campus as dozens of Sunday school teachers were being trained on how to deal with a shooter.

In the weeks after the shooting, family members described the boy as a normal teenager who was close to his family, loved wrestling with his father and brother, played in the church youth band and was known for his guitar solos.

His parents, Greg and Sarah Griego, were well-known throughout the community for more than a decade of ministry work with inmates at the county jail. Greg Griego, an Army veteran, also served as a pastor at one of Albuquerque’s largest Christian churches and was a volunteer chaplain with the local fire department.

Sheriff’s officials said the teen told detectives he was angry with his mother and had been having homicidal and suicidal thoughts.