DENVER >> The man who killed 10 people in a mass shooting at a Colorado grocery store in 2021 was convicted on Monday of first-degree murder and sentenced to life in prison without the possibility of parole.

Ahmad Al Aliwi Alissa, 25, had pleaded not guilty by reason of insanity. The jury instead found the Syria-born man guilty in Boulder District Court on 10 counts of first-degree murder. Jurors also found him guilty on dozens of counts of attempted murder and weapons offenses.

After relatives of the victims addressed the court, Judge Ingrid Bakke formally gave Alissa the mandatory sentence under Colorado law of life in prison without the possibility of parole.

Colorado Governor Jared Polis said in a statement that “though I know this guilty verdict won’t heal the pain so many of us feel, or bring back those who were killed, I hope that it can provide some peace.”

It was never in dispute that Alissa carried out the rampage. The case focused on his mental state at the time of the shootings. Under Colorado law, a person must be found to be unable to distinguish between right and wrong for an insanity defense to prevail.

Authorities said Alissa was armed with a legally purchased Ruger AR-556 pistol, which resembles an AR-15 semiautomatic rifle, when he entered the King Soopers grocery store in Boulder, about 30 miles (50 km) northwest of Denver, on March 22, 2021.

Alissa shot dead two people in the parking lot before entering the store and killing eight others, including a police officer who responded to the shooting.

“He is methodical and he is brutal,” District Attorney Michael Dougherty told jurors in closing arguments on Friday.

The psychologists and psychiatrists who testified during the trial that began last month agreed that Alissa was diagnosed as a schizophrenic who was profoundly mentally ill. But that diagnosis alone does not render a person legally insane.

“This tragedy was born out of disease, not choice,” defense attorney Kathryn Herold told the jury.

Eyewitnesses described Alissa as focused as he opened fire, shooting dead at least two victims at point-blank range after wounding them in the opening salvo.

Sarah Chen, a pharmacist working that day, testified during the trial that she heard Alissa shriek with delight as he fired his weapon as she and other workers crouched behind a counter.

“He said, ‘This is fun, this is so much fun,’” Chen testified.

Alissa did not testify in his own defense.

Erika Mahoney, whose father Kevin was killed in the shooting, told the court during victim impact statements on Monday that shortly after learning of her father’s murder she envisioned standing in court and facing the gunman.

“I wish the young man behind the gun had received more love in his life, because then maybe none of this would have happened,” Mahoney said.

She recounted other high-profile shootings that have plagued the United States in recent decades, and told the court ahead of Alissa’s sentencing: “To me, justice is putting an end to mass shootings in America.”