Update: James Holmes has been found guilty first degree of murder. Jurors convicted Colorado theater shooter James Holmes on Thursday in the chilling 2012 attack on defenseless moviegoers at a midnight Batman premiere, rejecting defense arguments that the former graduate student was insane and driven to murder by delusions.

The 27-year-old Holmes, who had been working toward his Ph.D. in neuroscience, could get the death penalty for the massacre that left 12 people dead and dozens of others wounded.

Jurors took about 13 hours over a day and a half to review all 165 charges. The same panel must now decide whether Holmes should pay with his life.

The verdict came almost three years after Holmes, dressed head-to-toe in body armor, slipped through the emergency exit of the darkened theater in suburban Denver and replaced the Hollywood violence of the movie “The Dark Knight Rises” with real human carnage.

CENTENNIAL, Colo. (AP) – The latest in the Colorado theater shooting trial (all times local):

Jurors have reached a verdict in the trial of Colorado theater shooter James Holmes.Gallery: Many faces of James Holmes

The panel made its decision Thursday after deliberating for a day and a half. A court spokesman says the verdict will be read at 4:15 p.m. MDT Thursday.

Holmes has pleaded not guilty by reason of insanity in the July 20, 2012, shootings that killed 12 people and injured 70 others.

If the jury convicts Holmes, the trial will enter a sentencing phase with testimony about whether he should be sent to prison for life or sentenced to death. Jurors make that decision.Gallery: Colorado Theater Shooting: Key Players

If they find him not guilty, he would be committed indefinitely to a state mental hospital.

Jurors heard nearly three months of testimony, including heartbreaking and sometimes gruesome survival stories.