More than three years after a gunman walked through a movie theater in Aurora, Colo., firing round after round into a packed crowd, a jury said Friday he should be spared a death sentence and instead spend the rest of his life in prison.

The same jurors who last month found James Holmes guilty on each of the 165 counts he faced for carrying out one of the worst mass shootings in U.S. history wound up spending little time deliberating on his penalty.

A death sentence could only be issued if every juror agreed, and all it takes is one vote for life in prison for that to become the sentence. After a lengthy, emotional trial, the jury said they could not reach a unanimous sentence on the counts facing Holmes, and as a result Holmes will be sent to prison without possibility of parole.

The jurors had previously turned down opportunities to sentence Holmes to life in prison, indicating twice during the final weeks of the trial that they thought a death sentence should remain on the table.

One by one, District Judge Carlos A. Samour Jr. read off the murder charges facing Holmes, who stood a few feet away with his hands in his pockets as the verdict was read. And one by one, he read from the verdict forms saying that since jurors had not all agreed on a sentence, they knew Holmes would be imprisoned for the rest of his life.

[After emotional trial, jury convicts James Holmes of murder for Aurora movie theater shooting]

Attorneys for Holmes had not denied that he was the man who killed 12 people and wounded another 70 during a screening of “The Dark Knight Rises” three years ago. Instead, they argued for a life sentence because they said he had suffered a psychotic break.

“James Holmes committed this crime because he was psychotic and delusional,” Tamara Brady, one of Holmes’s attorneys, said during the penalty phase’s closing arguments. She added: “The deaths of all of those people cannot be answered by another death. Please, no more death.”

George Brauchler, district attorney for Arapahoe County, called death “the only appropriate sentence in this case” during the final phase of the trial.

“You can bring justice to this act and to him,” Brauchler said during his final arguments in the case, pointing at Holmes. “And for James Egan Holmes, justice is death.”

After announcing that Holmes would not be sentenced to death, Samour thanked the jurors for their service and sacrifice during the trial.

Holmes had pleaded not guilty by reason of insanity, an argument the jurors rejected. His attorneys had said in a court filing two years ago that he was the gunman, writing that Holmes “was in the throes of a psychotic episode when he committed the acts that resulted in the tragic loss of life and injuries sustained by moviegoers on July 20, 2012.”

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Moviegoers had packed into a theater in Aurora, a suburb of Denver, for a midnight screening of a new Batman movie when a lone gunman caused the bloody carnage. Witnesses said Holmes calmly and silently strode through the theater, firing at adults and children alike.

His trial was pushed back multiple times by delays, including arguments over evaluations of Holmes’s sanity. Jury selection finally began in January, with opening statements following in April, allowing the trial to stretch over much of the year.

Relatives of those injured and slain marked the third anniversary of the shooting during the final weeks of the trial. Three days later, a gunman in Lafayette, La., opened fire inside a theater there, killing two other people and injuring nine others.

During the penalty phase, jurors weighing Holmes’s fate heard emotional testimonies from people who were injured or lost loved ones in the shooting. Ashley Moser, whose 6-year-old daughter, Veronica Moser-Sullivan, was killed in the attack, spoke Wednesday about her life since that night.

“I don’t know who I am anymore, because I was a mom when I was 18 and that’s all I knew how to be,” said Moser, who was paralyzed from the waist down during the shooting and suffered a miscarriage. Her voice breaking, she continued, “And now I’m not a mom.”

Relatives of Holmes who had pleaded for a life sentence also spoke during the trial about what he was like in the years before the shooting. Holmes’s father, Robert, said he still loved him because because “he’s my son.” The older Holmes added: “He was always a really excellent kid.”

Holmes had faced 165 total charges in this case, nearly all of them for murder or attempted murder. He was also charged with one count of possessing an explosive device. Holmes was found guilty on every single charge.

Jurors had debated whether to make Holmes the fourth person on Colorado’s death row. Death row inmates spent 23 hours a day alone in solitary cells at the state’s Sterling Correctional Facility, about 125 miles northeast of Denver; when their execution date nears, inmates are moved to a different penitentiary before the lethal injection.

But death sentences are rare in Colorado. Between 1973 and 2013, the state sentenced 22 people to death, according to the Justice Department. More people were sentenced to death in 30 other states and by the federal government over the same period.

Colorado is also among the least active death-penalty states in the country. Since the Supreme Court reinstated the death penalty in 1976, only one inmate has been executed there.

A life sentence averts a lengthy process of appeals and a long delay before a possible execution. Death row inmates nationwide have spent an average of 14 years under their sentences, and the Colorado Department of Corrections notes that due to appeals, inmates will spend at least a decade on death row.

People in Colorado had said by a nearly two-to-one margin that they wanted Holmes to receive a death penalty rather than life in prison, according to a Quinnipiac University Poll released last month. While 63 percent of voters supported a death sentence, 32 percent favored imprisonment.

Holmes’s parents had pleaded for their son’s life before the trial began, writing that they know people view their son as a monster.

“We do not know how many victims of the theater shooting would like to see our son killed,” Robert and Arlene Holmes wrote in a letter published by the Denver Post. They also wrote: “He is not a monster. He is a human being gripped by a severe mental illness.”

They had asked for their son to spend the rest of his life imprisoned rather than be sentenced to die.

Holmes still has to be formally sentenced, which Samour scheduled to occur later this month.

Related:

The Boston Marathon bomber was sentenced to death, but the government can’t execute anyone right now

This post has been updated and will be updated again. First published: 4:40 p.m.