The defendant in a 2021 mass shooting that killed 10 people at a Colorado supermarket pleaded not guilty by reason of insanity on Tuesday as a judge ruled that the case can move to trial.

Defense attorneys for defendant Ahmad Al Aliwi Alissa entered the plea on his behalf during a hearing before Judge Ingrid Bakke in Boulder.

A plea of not guilty by reason of insanity involves whether someone’s mental health prevented them from understanding right from wrong when a crime was committed.

Alissa is charged with murder and multiple attempted murder counts. Neither his attorneys nor anyone else has disputed that he was the gunman. A forensic psychologist testified during a hearing in September that the 24-year-old Alissa bought firearms to carry out a mass shooting and indicated “there was some intention to commit suicide by cop.” Alissa, dressed in an orange and white striped jail uniform, looked down and at the judge at times as she advised him of rights about entering the insanity plea.

THIS IS A BREAKING NEWS UPDATE. AP’s earlier story follows below.

DENVER (AP) — It took just over a minute for the gunman in a 2021 mass shooting to kill most of his victims at a Colorado supermarket, where he targeted individuals who were moving and continued firing at them until they were dead, a police detective testified Tuesday.

Ten people including a police officer were killed in the attack at a crowded King Soopers store in the college town of Boulder. The first eight victims died within 69 seconds; all but one were shot multiple times and everyone who was shot was killed, Boulder Police Detective Sarah Cantu said Tuesday.

“He found moving targets, pursued them and shot them until they stopped moving,” Cantu said as prosecutors laid out their case against a mentally ill man recently deemed competent to stand trial in the March 22, 2021, shooting.

The hearing was to decide if there was enough evidence for defendant Ahmad Al Aliwi Alissa, who has schizophrenia, to go on trial in the shooting about 30 miles (50 kilometers) northwest of Denver. Judge Ingrid Bakke ruled after Cantu’s testimony that the case can move to trial.

Authorities have not determined a motive, Cantu said. But a forensic psychologist testified during a hearing in September that the 24-year-old Alissa bought firearms to carry out a mass shooting and indicated “there was some intention to commit suicide by cop.”

Alissa, who is charged with murder and multiple attempted murder counts, has not been asked to enter a plea yet. But neither his attorneys nor anyone else has disputed that he was the gunman.

At the September hearing, a forensic psychologist, Loandra Torres, also told the judge that Alissa knows his fingerprints were found on guns that could be used as evidence against him. He was arrested in the store after being shot by a police officer.

Tuesday’s hearing is the next required step in his prosecution, which until recently had been stalled because of Alissa’s mental health.

For families of victims, it is an important milestone. Robert Olds, whose niece Rikki Olds was killed, was in the front row of the courtroom. He said he wanted justice on behalf of his niece, a 25-year-old front-end manager at the supermarket.

“It’s the last fight, the last stand for my niece who can’t be here to do that herself because this guy murdered her,” Robert Olds said.

Alissa sat at the defense table wearing a striped jail jumpsuit, next to two of his lawyers and with four deputies nearby.

He’s accused of killing nine shoppers and workers inside and outside the store as well as Officer Eric Talley, a father of seven and one of the first three police officers who entered the store. The dead included Denny Stong, Neven Stanisic, Tralona Bartkowiak, Teri Leiker, Suzanne Fountain, Kevin Mahoney, Lynn Murray and Jody Waters.

Authorities have said Alissa legally purchased the AR-556 pistol, which resembles a rifle, used in the attack. The families of some of the victims are suing its manufacturer, Sturm, Ruger & Co., saying it markets the gun in a “reckless” and “immoral” way that promoted its killing capability and glorified lone gunmen. In a court filing, the company said its marketing does not promote illegal activity and that the lawsuit is trying to unconstitutionally punish its lawful and protected commercial speech.

Alissa was declared mentally incompetent in late 2021 and sent to the state mental hospital for treatment. After he was forcibly medicated, experts this summer said his condition had improved significantly. Last month, Bakke ruled that Alissa was competent to be prosecuted over the objections of the defense after hearing testimony from psychologists.

Another psychologist who testified for the prosecution at the September hearing, Julie Gallagher, attributed the length of time it took for Alissa to reach mental competency to the severity of his illness.

Initial evaluations throughout 2021 and 2022 found Alissa incompetent for trial largely due to his inability to communicate clearly and at times his outright refusal to discuss the allegations against him, Torres testified.

Mental competency involves whether a defendant is able to understand court proceedings and communicate with his lawyers to help his own defense. It is a different legal issue than a plea of not guilty by reason of insanity, which involves whether someone’s mental health prevented them from understanding right from wrong when a crime was committed.

Alissa’s family immigrated from Syria, he became a U.S. citizen and they lived in a middle-class neighborhood in a Denver suburb, where the family also had a restaurant.

The only known problem prior to the shooting was in 2018 when Alissa was convicted of assaulting a fellow high school student, a misdemeanor, according to police documents. A former classmate also told The Associated Press that Alissa was kicked off the wrestling team after yelling he would kill everyone following a loss in a practice match.

The supermarket shooting ended after Alissa was wounded by a police officer who was part of a second wave of law enforcement that entered the store after Talley was killed.

(AP)