James Holmes has been found guilty of murder during the July 2012 movie theater shooting in Aurora, Colo.
A jury decided Thursday that Holmes is responsible for killing 12 people in the attack three years ago in the Denver area.
{mosads}Nine women and three men decided Holmes’s fate on the trial’s 51st day of proceedings at the Arapahoe County Courthouse in Littleton, Colo.
They deliberated for 13 hours before ruling that Holmes is guilty of 24 counts of murder in the first degree. For each of the 12 victims, prosecutors brought separate charges of first-degree murder with intent and first-degree murder with extreme difference.
The attack took place during a midnight screening of “The Dark Knight Rises” at a cinema in Aurora on July 20, 2012.
Twelve people died during the incident, and another 70 were injured.
Holmes, 27, next faces sentencing. He could receive the death penalty or life in prison.
In addition to the 24 counts of first-degree murder, Holmes faced 140 counts of attempted murder and an explosives count, NBC said.
Holmes’s defense attorneys argued during the trial’s proceedings that he was mentally insane during the 2012 rampage.
The former doctoral student in neuroscience at the University of Colorado-Denver reportedly suffered from schizophrenia.
Holmes would have likely been committed to a mental institution had he been found not guilty by reason of insanity for all of the charges against him.
Thursday’s ruling rejects the defense that his mental state made him unaccountable for the shooting.
Updated at 6:50 p.m.