James Holmes on Monday formally changed his plea from not guilty to "not guilty by reason of insanity" for the July 20, 2012, movie theater shooting rampage in Aurora, Colo., that left 12 people dead and an additional 70 injured.
Holmes' lawyers had said last week that the young man would be doing this.
After his attorneys said they need more time to prepare to respond to the 166 counts of murder, attempted murder and other crimes he faces, a Colorado judge on Tuesday entered a not guilty plea on behalf of accused movie theater gunman James Holmes.