CENTENNIAL — James Holmes is guilty of murder for killing 12 people in an Aurora movie theater three years ago, a jury decided Thursday, ending the legal limbo for one of the worst mass shootings in American history.

In count after emphatic count, jurors rejected the defense’s argument that what happened at the Century Aurora 16 theater on July 20, 2012, was a tragic act of insanity. It was a deliberate crime, jurors said.

Holmes now faces possible execution as punishment.

The jury of nine women and three men found Holmes guilty of 24 counts of first-degree murder — two for each victim slain — as well as 134 counts of first-degree attempted murder, six counts of attempted second-degree murder and one count of explosives possession.

In the wood-paneled courtroom before the verdict was read, tension pulled the spectators taut. Parents who lost their children in the attack held hands with clenched grips. Holmes’ parents leaned stiffly against one another, a box of tissues resting on Robert Holmes’ lap.

Then, over a single, unrelenting hour in Arapahoe County courtroom 201, Judge Carlos Samour Jr. called out the word “guilty” 165 times — all but one time attaching to the verdict the name of someone whose life was irrevocably altered during the shooting.

Count 1. Murder in the first degree after deliberation — Jonathan Blunk.

“We the jury,” Samour read from the verdict form, “find the defendant, James Eagan Holmes, guilty.”

And in the audience, family members of the victims pressed their hands over their mouths to stifle outcries of relief because — after a wait of nearly three years — they finally knew the man who killed their loved ones would never go free again.

Emotions pinged across the courtroom as Samour continued reading.

Count 4. Guilty.

Brooke Cowden softly closed her eyes at the recognition of justice for her father, Gordon, who took her to the movies that night and whose body she had to step over to escape the gunfire.

Count 5. Guilty.

Sandy Phillips pressed to her lips the green scarf she wore every day during the trial, the one that belonged to her slain daughter, Jessica Ghawi. The scarf made her feel like Jessi was giving her a hug, Phillips said.

Count 6. Guilty.

Kathleen Larimer crumpled forward in her chair, then leaned back and let the tears for her son, John, wash over her cheeks. At long last, she exhaled.

Count 11. Guilty.

Tom Teves held his wife’s hand tightly and glared forward at the man who took his son, Alex, from him.

Samour just kept reading.

Count 12.

“We the jury…”

Count 35.

” … find the defendant … “

Count 98.

” … James Eagan Holmes … “

Count 165.

” … guilty.”

Shooting survivor Joshua Nowlan, wearing a short-sleeve shirt that revealed the bullet scar on his right arm, waited 50 counts to hear the first of the charges pertaining to him. Guilty. He closed his eyes and nodded his head in stoic approval.

At the judge’s command, the defendant stood for the length of the verdict’s reading. Holmes — now 27, bearded and several pounds heavier than the red-haired wisp who shuffled into the same courtroom for his first appearance — put his hands in his pockets and appeared to show little emotion. In the second row of chairs behind him, his parents stared blankly at the seatbacks in front of them.

Throughout the trial, prosecutors argued that the shooting, planned for months in advance, was a calculated act by a selfish man who wanted to kill others to make himself feel better. Holmes, a former neuroscience graduate student at the University of Colorado, had recently broken up with his girlfriend, failed a crucial exam and dropped out of school.

The defense countered that the shooting was the result of a delusional belief by Holmes — who has been diagnosed repeatedly with some form of schizophrenia — that killing would boost his “human capital.” They painted him as a man controlled by his thoughts.

It took jurors less than 13 hours of deliberating over two days to make up their minds. At least part of that time was spent filling out paperwork, as the foreman — a survivor of the Columbine High School shooting — had to sign his name 329 times on the 659 pages of verdict forms.

When the jury gathered in the courtroom around 4 p.m., the foreman delivered the verdict to Samour in five manila envelopes. One juror appeared to wipe tears from her eyes. Another looked out into the victims’ side of the courtroom gallery.

For each of the 12 slain victims and the 70 wounded victims, Holmes was found guilty of two counts. One count alleged first-degree murder or attempted murder after deliberation. The other alleged first-degree murder or attempted murder with extreme indifference.

The only variation in the jury’s verdict came from three survivors who were sitting in an adjacent theater to Theater No. 9, where the shooting took place. Jurors found them the victims of attempted second-degree murder after they were wounded by bullets that burst through the wall.

Jurors also convicted Holmes of possessing explosives, which he rigged with gunpowder and gasoline and homemade napalm for what he later told authorities was intended to be a fire that would divert authorities away from the theater.

The case now moves to a death penalty sentencing phase. On Monday, the third anniversary of the shooting, prosecutors and defense attorneys will return to court to debate legal issues surrounding Colorado’s death penalty procedures — which haven’t been used at trial since 2009, when a jury in Arapahoe County sentenced Robert Ray to death.

Jurors will return again to the courtroom on Wednesday for the start of the sentencing phase, which could last several weeks and will likely include a new deluge of emotional testimony — from victims, from survivors, from the parents of the convicted, all hoping for a ray of justice.

On Thursday, as Samour read the verdict, rain began falling outside the courthouse — one of those Colorado storms where it pours and the sun shines at the same moment. Then it cleared, and a rainbow bloomed just out of reach in the distance.

“I think it’s a relief, but it’s sad,” said Katie Medley, standing outside the courthouse after the verdict. She was wounded during the shooting; her husband, Caleb, was paralyzed.

“We were in a room full of people that lost their sons and daughters.”

John Ingold: 303-954-1068, jingold@denverpost.com or twitter.com/johningold

Staff writers Jesse Paul, Noelle Phillips and John Aguilar contributed to this report.