BOULDER, Colo. (AP) — A hearing begins Wednesday to determine if the man accused of killing 10 people at a Colorado supermarket in 2021 is mentally competent to stand trial.

Ahmad Al Aliwi Alissa, 24, was found mentally competent by experts at the state mental hospital in August, but his defense attorney Kathryn Herold asked for the determination to be debated in court.

Judge Ingrid Bakke was required to schedule the two-day hearing that will include testimony but denied Herold’s request for another evaluation from the mental hospital. Bakke’s ruling could come as soon as Thursday.

Herold argued at the time that Alissa, who has schizophrenia, is not competent and cited the psychiatric evaluations describing him as “profoundly mentally ill.”

Schizophrenia can shake someone’s grasp on reality, potentially interfering in a legal defense in court. Mental competency to move toward trial entails Alissa being able to understand court proceedings and help Herold with his defense. It does not mean he’s been cured.

Mental competency is also separate from pleading not guilty by reason of insanity, which is a claim that someone’s mental health prevented them from understanding right from wrong when a crime was committed.

The August evaluation was the first that ruled Alissa competent. The case has been on hold for two years while victims and families of those killed are eager for it to move forward.

Experts at the mental hospital determined Alissa was competent because he was consistently taking medication and in a stable therapeutic environment, according to prosecutors in August, who added that his competency is “tenuous.”

Alissa is charged with murder and multiple attempted murder counts after the shooting spree began on March 22, 2021, in a crowded King Soopers store in Boulder, about 30 miles (50 kilometers) northwest of Denver. Alissa has not yet been asked to enter a plea.

Alissa allegedly began firing outside the grocery store, shooting at least one person in the parking lot before moving inside, employees told investigators. Employees and customers scrambled to escape the violence, some leaving loading docks in the back and others sheltering in nearby shops.

A SWAT team with ballistic shields approached the store and law enforcement took Alissa into custody.

Authorities haven’t yet disclosed a motive for the shooting, and little is known about why he carried it out. Alissa was convicted of assaulting a fellow high school student in 2018, according to police documents, but that remains one of the only known crimes involving Alissa prior to the shooting.

While hospital reports on Alissa aren’t made public under Colorado law, his lawyers confirmed in February through court filings that he was diagnosed with schizophrenia, adding that he struggles to tolerate extended contact with other people.

Last year, the remodeled King Soopers reopened, with about half of those who worked there previously choosing to return.