Colorado movie gunman James Holmes to receive 12 life sentences and more
James Holmes and his defense attorney Daniel King (R) sit in court for an advisement hearing at the Arapahoe County Justice Center in Centennial, Colorado on June 4, 2013. REUTERS/Andy Cross/Pool

The judge in the Colorado movie massacre trial will condemn the gunman to 12 life sentences and potentially thousands more years in prison on Wednesday, and is expected to address James Holmes directly as the proceedings conclude.

Holmes was found guilty in July of murdering 12 people and wounding 70 when he opened fire inside a packed midnight screening of a Batman film at a multiplex in the Denver suburb of Aurora.

The jury did not reach a unanimous decision on whether he should be executed. That meant the former neuroscience graduate student, who had pleaded insanity, got a dozen automatic life sentences with no possibility of parole.

After two days of often tearful and sometimes angry testimony from victims of Holmes' July 2012 rampage, the lead prosecutor said on Tuesday the shooter should get every day of the longest possible sentence.

"The maximum sentence for the maximum evil, your honor," District Attorney George Brauchler told the judge.

He said he wished the court could order Holmes to spend the rest of his days in solitary confinement, surrounded by photos of the people he killed, but that it could not.

Neither could it order Holmes to be miserable, he said, or to make no more friends.

"So what we have is a period of time," Brauchler said.

Defense lawyers have said they have no plans to appeal.

Holmes was found guilty of 165 counts of first degree murder, attempted murder and an explosives charge for rigging his apartment with homemade bombs.

While the California native will receive life sentences on the murder charges, Arapahoe County District Court Judge Carlos Samour must still decide his punishment on the other counts.

Prosecutors have said the gunman could ultimately be sentenced to a maximum of 3,318 years in prison, in addition to the mandatory life sentences.

Following this week's accounts from victims, some of whom called Holmes a monster and said they were sorry that his life had been spared, his mother Arlene addressed the court.

Like her husband, she had testified earlier during the trial that schizophrenia was to blame for their son's actions, and she said on Tuesday that the couple pray for those left behind.

"We do not refer to ourselves as victims because we cannot be placed in the same category as everyone else. We cannot feel the depths of your pain," she said.

"We are very sorry this tragedy has happened, and sorry that everyone has suffered so much."