Opening statements are scheduled in the trial of a man who killed 10 at a Colorado supermarket

DENVER — Opening statements are scheduled for Thursday in the trial of a mentally ill man who 10 people shot dead in a Colorado supermarket in 2021.

The police say Ahmad Al Aliwi Alissa targeted people moving both inside and outside the store in the college town of Boulder, killing most of them in just over a minute.

No one, including Alissa’s lawyers, disputes that he was the shooter. Alissa, who was diagnosed with schizophrenia after the shooting, has pleaded not guilty by reason of insanity so the three-week trial is expected to focus on whether he was legally sane — able to understand the difference between right and wrong — at the time of the shooting.

Alissa is charged with 10 counts of first-degree murder, multiple counts of attempted murder and other crimes, including banning six large-capacity magazines in Colorado after previous mass shootings.

It’s up to prosecutors to prove he was sane. They have to show that Alissa knew what he was doing and planned to kill people in the King Soopers.

Why Alissa carried out the mass shooting remains unknown.

The closest anyone has come to a possible motive was when a mental health expert testified at a hearing last year that Alissa had said he had purchased guns to carry out a mass shooting and wanted police to kill him.

The defense argued in a court filing that family members said he irrationally believed the FBI was following him and that he talked to himself as if he were speaking to someone who wasn’t there. Prosecutors, however, point out that Alissa had never previously been treated for mental illness and was able to work up to 60 hours a week leading up to the shooting, something they say would not have been possible for someone with severe mental illness.

Alissa’s trial has been postponed because experts repeatedly found he could not understand the proceedings and could not help his defense. But after Alissa improved after being forcibly medicated, Judge Ingrid Bakke ruled in October that he was mentally competent, allowing the proceedings to resume.