ALBUQUERQUE, N.M. » A judge cleared the way today for a New Mexico teenager who shot and killed his parents and three younger siblings to be sentenced as a juvenile and released from state custody by the time he turns 21 after the teen’s attorneys argued he could be psychologically rehabilitated.

Nehemiah Griego was 15 when he opened fire in his family’s home south of Albuquerque, killing his mother as she slept and then his 9-year-old brother and two sisters, ages 5 and 2, authorities said. Griego’s father was the last to die: The teen waited in a bathroom and ambushed the gang member turned pastor after he returned home, sheriff’s officials said.

Now 18, Griego has undergone nearly two years of therapy at a state adolescent treatment center — where his teachers, psychiatrists and others say he has made significant progress after being diagnosed with schizoaffective disorder, post-traumatic stress disorder and some learning disabilities.

“It all points in the same direction,” said Jeffrey Buckels, Griego’s public defender. “He’s getting better and deserves a chance.”

Judge John Romero ruled on Griego’s treatment after a lengthy hearing in children’s court to determine whether he could be psychologically rehabilitated and sentenced as a juvenile, which allows his release from state custody in just more than two years. Griego turns 21 in March 2018.

He pleaded guilty in October to two counts of second-degree murder for his parents’ deaths and three counts of child abuse resulting in death, which his attorney said showed he had taken responsibility for the crime.

Prosecutor Michelle Pato countered that assertion, recalling testimony in the hearing from some who said Griego seemed matter of fact and emotionless the day after the shooting and during a psychiatrist’s interview last year.

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 in the days after the shooting, Griego spent much of the day wandering the campus at Calvary Church, an Albuquerque megachurch where his father had been a pastor.

In closing arguments, Pato described the January 2013 killings as predatory and cold-blooded, with Griego waking his younger brother to show him his mother’s body before shooting the 9-year-old too. Griego took a photo of the two victims before shooting his younger sisters in their beds, Pato said.

“He played with his brother that day knowing he was going to kill him,” Pato said. “This was very much planned, very thought out and cruel.”

As chilling as details of the crime may have been, Judge Romero, however, said state law called for the hearing and his findings to focus on Griego and his prospects for rehabilitation, not the offense.

Defense attorneys’ case presented a narrative of a teen who grew up in a chaotic environment, enduring emotional abuse by his mother and physical abuse at the hands of his father that likely led to a traumatic brain injury.

A residential supervisor at Sequoyah Lodge, where Griego is undergoing treatment, said the 18-year-old had matured into a role model for other troubled boys, while one teacher described the teen as a thoughtful student despite having expressed racist viewpoints, a fascination with war and Nazi Germany, and the notion of absolute power.

A forensic psychologist for the defense said he recommended Griego receive five more years of treatment, despite the likeliness that Griego’s treatment at Sequoyah Lodge would likely end in 2018. The judge didn’t rule Thursday on continuing Griego’s treatment after he turns 21.

A hearing will be held to sentence Griego as a juvenile in three to six weeks.