DENVER (AP) — A hearing to determine whether a man charged with killing 10 people at a Colorado supermarket will stand trial is being delayed after his lawyers said they believe he has a “mental disability” that prevents him from being able to understand proceedings or help them defend him.

BOULDER, CO – MAY 25: Ahmad Al Aliwi Alissa appears in a Boulder County District courtroom at the Boulder County Justice Center on Tuesday, May 25, 2021. (credit: CBS)

In an order Thursday, Judge Ingrid Seftar Bakke agreed to postpone Tuesday’s preliminary hearing to review the evidence against Ahmad Alissa, as requested by his lawyers. Instead, she said she would use the time to advise Alissa of his rights during the process to determine if he is mentally competent and order an evaluation for him.

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A defendant’s ability to understand and assist in their defense is a separate legal issue than a plea of not guilty by reason of insanity, which hinges on whether someone’s mental health prevented them from knowing right from wrong when the crime was committed.

(credit: CBS)

Prosecutors, upset that the defense first raised the issue of competency less than a week before the hearing, had asked that the preliminary hearing, scheduled back in May, move ahead as planned because shooting victims and their families had already made plans to attend it, with some traveling from around the state and the country.

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The defense initially raised unspecified concerns about Alissa’s mental health right after the March 22 shooting and said it needed time to evaluate him. They did not raise the issue again in court until Wednesday, when one of Alissa’s lawyers filed a motion raising concerns about his competency. The filing is sealed as required by state law so the details of the concerns are not known.

However, in a public filing asking to delay next week’s hearing, Alissa’s lawyers said they have a “reasonable belief” that he suffers from a “mental disability” based on personal interactions with Alissa, information from family members and others, evidence in the case and professional opinion. They also noted that they only got an expert’s determination on Alissa’s mental health on Tuesday night.

By COLLEEN SLEVIN Associated Press

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