MANCHESTER, N.H. -- A bid for a reduced sentence for a New Hampshire man who was 17 when he wielded a machete and killed a woman during a Mont Vernon home invasion may be heard as early as January.

Steven Spader was sentenced to life in prison for hacking to death Kimberly Cates and wounding her daughter, Jaimie, in 2009.

His lawyer cited a recent U.S. Supreme Court ruling that mandatory life sentences for those under 18 are cruel and unusual punishment.

“Right now the sentence as it stands is illegal,” said Jonathan Cohen, Spader’s attorney. “The reason for that is because a juvenile is fundamentally different than an adult…Their brains are not fully formed, their decision making is not fully formed and for those reasons the sentencing has to consider those differences.”

Wednesday's hearing in Manchester was a scheduling conference in the judge's chambers. Spader's lawyer was given until Dec. 28 to introduce expert psychiatric testimony. Another meeting is scheduled for Jan. 3.

“It’s kind of another blow, but we explained to them when this began that this would be a lengthy process of years,” said Jeff Strelzin, Sr. Asst. Attorney General.

Prosecutors anticipate the hearing on Spader's bid could happen as early as January if no defense expert reports are submitted.

Spader’s conviction cannot be overturned and a judge can still impose a life sentence, which the state will ask for.

“He was charged with committing the case purposely, under the law in New Hampshire for first-degree murder that includes an element of premeditation deliberation. That’s what he was charged with. That’s what we proved beyond a reasonable doubt,” said Strelzin.

There were three other defendants found guilty in this case, however two of them plead guilty to second-degree murder charges and the third was a teen at the time. None of the other trials will be affected by this new decision.

The Associated Press contributed to this report.