A U.S. judge has accepted a plea of not guilty by reason of insanity from the accused shooter in last year's movie theater massacre in Colorado.
The 25-year-old suspect, James Holmes, entered the plea Tuesday. He is charged with killing 12 people and wounding 70 others last July, when he opened fire on an audience watching a Batman movie at a theater in the Denver area.
The massacre was one of several mass shootings that reignited a long-running debate in the United States about how to deal with gun violence and people with mental health problems.
Holmes must now undergo a mental evaluation to determine if he truly was insane at the time of the shootings -- a process that could take months.
Prosecutors have dismissed the insanity claims. They say Holmes methodically planned his attack, using several weapons to fire on cinema-goers.
A jury could still find Holmes guilty of more than 160 counts of murder, attempted murder and other crimes he faces, which could bring the death penalty.