Defense lawyers representing Colorado theater shooter James Holmes wrapped up their case on Friday.

Throughout the trial, the defense argued that the 27-year-old mass murderer was clinically insane when he opened fire at an Aurora movie theater showing the "Dark Knight" on July 20, 2012. As a result, 12 moviegoers were killed, while 70 others were injured. The former neuroscience graduate student is now on trial for first-degree murder, attempted murder and an explosives offense. If convicted, he will face the death penalty. However, he has pleaded not guilty by reason of insanity.

According to the defense, the shooter suffers from schizophrenia and could not tell right from wrong when he intentionally killed people at the movie premiere.

During the trial, defense expert Raquel Gur, the director of the Schizophrenia Research Center at the University of Pennsylvania, gave a four-day testimony explaining and defending her diagnosis that Holmes was legally insane.

"He was not capable of differentiating between right and wrong," said the star witness on Thursday, according to Reuters. "He was not capable of understanding that the people that he was going to kill wanted to live."

Prosecutors, on the other hand, accuse Holmes of being a cold-blooded killer. Two court-appointed psychiatrists also made mention of their research that shows that though Holmes is severely mentally ill, they have told jurors, he was legally sane when he planned and executed the massacre.

Before resting their case, the defense played two videos of Holmes acting erratically. In one video, he is seen wearing no clothes and running head-long into a cell wall. The other video captures him thrashing around while splayed in restraints on a hospital bed.

When asked if he wanted to take the stand on Thursday, Holmes declined to testify in his own defense on Thursday.

"I choose not to testify," he told Arapahoe County District Court Judge Carlos Samour, reports CNN.

Both lawyers in the case are scheduled to deliver closing remarks on Tuesday. The jury is then expected to begin deliberating the next day.