Boulder King Soopers shooter found guilty on all 55 counts

The man who killed 10 people in a 2021 shooting at a Boulder King Soopers grocery store was found guilty of murder in a landmark verdict Monday that will send him to prison for life.

Why it matters: The attack and trial shook Colorado despite the state's grim familiarity with mass shootings.

Driving the news: The question before 12 jurors in a Boulder County courtroom was whether Ahmad Al Aliwi Alissa, 25, was sane at the time he carried out the shooting.

The jury outright rejected the argument, deciding he was sane. The judge read the verdict just after 1:30pm. The jury found Alissa guilty on the first 10 murder charges and subsequent weapons charges related to the shooting.

• Colorado abolished the death penalty so Alissa, who was 21 at the time of the shooting, will spend his life behind bars.

Catch up quick: The jury began deliberating Friday after three weeks of testimony.

• Alissa pleaded not guilty by reason of insanity and the trial was delayed for years after experts repeatedly deemed him unfit .

The big picture: His attorneys claim he was experiencing a "psychotic episode" due to severe, untreated schizophrenia at the time of the rampage.

• But prosecutors countered the shooting was "planned, deliberate and intentional," and that he knew right from wrong.

Zoom in: Those killed in the shooting: Boulder police officer Eric Talley, Rikki Olds, Teri Leiker, Denny Stong, Suzanne Fountain, Tralona Bartkowiak, Neven Stanisic, Lynn Murray, Jody Waters, and Kevin Mahoney,

• The judge sentenced Alissa to more than 1,300 years in prison, to be served consecutively, on all 38 counts of attempted first-degree murder, assault and illegally possessing a high-capacity magazine.

Inside the room: The verdict didn't appear to affect Alissa. He tottered in his seat and talked with his lawyer.

• The victims' relatives shed tears as the judge read "guilty" 55 times, the Denver Post reported . Police officers took deep breaths for their fallen comrade.

What they're saying: Moments after the verdict, the families of the victims spent an hour reading statements about the pain of the loss of their relatives ahead of the formal sentencing.

• "To me, justice is putting an end to mass shootings in America," said Erika Mahoney, whose father Kevin Mahoney was shot to death in the grocery store parking lot. "This all needs to stop."