'Dark Knight Rises' Gunman James Holmes is Sentenced to Life in Prison Without Parole

Colorado movie theater shooter James Holmes was sentenced to life in prison without parole.

Colorado movie theater shooter James Holmes was formally sentenced to life in prison without parole on Wednesday.

Read: Movie Theaters Screening 'Straight Outta Compton' Beef Up Security

A Colorado judge condemned the 27-year-old to 12 life sentences and the maximum 3,318 years in prison for his 2012 rampage.

The sentencing comes more than three years after Holmes opened fire at a movie theater in Aurora during a screening of The Dark Knight Rises.

Judge Carlos A. Samour Jr. had no other sentencing option after the jury did not unanimously agree that Holmes should get the death penalty.

"It is almost impossible to comprehend how a human being is capable of such acts," the judge said.

Holmes killed 12 people and injured 70 others in the July 20, 2012 ambush. He was convicted of first-degree murder and 140 counts of attempted first degree murder, as well as an explosives charge.

On Tuesday, the killer's mother, Arlene, apologized to the victims' familes. She said that she is "very sorry that this tragedy happened and that everyone has suffered so much."

She added: "We are in a unique and unenviable position because we cry for James and we cry for thousands of people in Aurora.

"We cannot feel the depth of your pain. We can only listen to everything you have expressed, and we pray for you. We pray for your peace, your peace with the sentence. We pray for your ability to sleep at night, and your ability to find a single moment of happiness when that happiness seems completely elusive."

Arlene also mentioned that James "said he feels remorse for his horrible actions. But his ability to express his emotions has been impaired by disease and medication and we know it is very, very hard for people to see."

Read: Who is Louisiana Movie Theater Shooter John Russel Houser?

Jurors rejected Holmes' insanity plea, convicting him of murdering 12 people and trying to kill 70 others when he opened fire on a packed theater in suburban Denver on July 20, 2012.

Watch Below: Keep Hidden and Don't Run: What to do During a Movie Theater Shooting