FILE - Nehemiah Griego, 15, is seen in an undated photo provided by the Bernalillo County Sheriff's Deptartment. Two older sisters of Griego, who pleaded guilty to killing his parents and three younger siblings when he was a teenager, said Tuesday, Jan. 23, 2018, they forgive their brother but still want justice for their family. (Bernalillo County Sheriff's Department, File)

ALBUQUERQUE, N.M. - A New Mexico prosecutor made an 11th-hour attempt Wednesday to persuade judges to overturn the sentence of a New Mexico man who killed five family members when he was a teenager and is set to be released in March.

In oral arguments, John Woykovsky with the New Mexico Attorney General's Office argued before the state Court of Appeals that a lower court opinion two years ago to sentence Nehemiah Griego as a juvenile failed to take into account several key factors as the law requires — including the severity of the crime, the fact that Griego carried out the January 2013 rampage with a firearm, and that it had been premeditated.

In the 2016 ruling, a Children's Court judge found Griego had shown he was receptive to psychological treatment while in state custody after being diagnosed with schizoaffective disorder, post-traumatic stress disorder and some learning disabilities. The decision cleared the way for Griego's release on his 21st birthday, which is March 20.

"The real question is can he be fixed by the time he's 21 in such a way that protects the public interest," Woykovsky said.

He argued that Children's Court Judge John Romero's decision hadn't properly addressed the question, and that there had been no testimony during a 2016 hearing to definitely determine that was the case.

Griego was 15 when authorities say he killed his parents, Greg and Sarah Griego, and three younger siblings — Zephaniah, Jael and Angelina — at the family's home south of Albuquerque. He first shot his mother in her bed as she slept, then his 9-year-old brother, and then his two sisters, ages 5 and 2, according to Bernalillo County Sheriff's officials.

Griego's father was the last to die, after he returned home five hours later. The teen — who had been waiting in a bathroom — had ambushed him, authorities said.

Prosecutors said that Griego carried out the shooting after his mother yelled at him earlier that day, while defence attorneys have long argued in his defence that he had been abused at home and likely suffered a traumatic brain injury as a result of his father's beatings.

They described the family's home as chaotic, and their lifestyle largely isolated, aside from church outings. Griego's father, a reformed gang member, had been a pastor at one of Albuquerque's largest Christian churches.

After days of testimony in 2016 from expert witnesses, sheriff's deputies, and Griego's teachers and psychiatrists at a state facility for adolescents, Judge John Romero found that Griego had made significant progress toward rehabilitation.

The attorney general is seeking to have the case sent back to Children's Court for further hearings. Attorney General Hector Balderas, however, would not say what his office hoped the final outcome of those hearings would be if it wins in its appeal.

Theodosia Johnson, a defence attorney, countered Woykovsky's arguments, saying Judge Romero had, in fact, noted the crime's severity, with a reference in court to testimony calling it horrific.

"What it is to sentence a child as an adult is an election to give up on that child, and Judge Romero did not give up on Nehemiah," she said.

Griego did not attend the hearing Wednesday, but his older sisters who are supporting the attorney general's appeal were there.

The three-judge panel did not say when they would issue a ruling.

News from © The Associated Press, 2018