Opening statements begin in Colorado theater shooting trial

CENTENNIAL, Colo. -- Opening statements have begun in the long-awaited death penalty trial of Colorado movie theater shooter James Holmes.

Holmes has pleaded not guilty by reason of insanity to killing 12 people and injuring 70 when he opened fire at a midnight showing of a Batman movie in suburban Denver.

The July 20, 2012, mass shooting was one of America's deadliest.

Holmes' attorneys say he was in the throes of a psychotic episode and couldn't tell right from wrong.

But prosecutors allege he planned the violence for months, amassing an arsenal that included guns, tear gas and body armor. They say he also stockpiled chemicals to rig his apartment into a potentially lethal booby trap.

The trial comes after attorneys and a judge spent 2 years hashing out legal questions and selecting a jury.