CENTENNIAL, Colo. - A Colorado judge says there's enough evidence for James Holmes to face trial on charges that allege he killed 12 people and injured 70 others in a movie theater last summer.

Judge William Sylvester said Thursday that prosecutors have established probable cause on more than 160 felony counts.

Holmes is due to be arraigned Friday, but his defense attorneys filed papers Thursday saying he's not ready to enter a plea. They are likely to ask for the arraignment to be delayed.

Holmes, who grew up in San Diego, is charged with more than 160 counts including murder and attempted murder.

Investigators say Holmes, who grew up in San Diego, was wearing body armor and a gas mask when he tossed two gas canisters and then opened fire in a theater in the Denver suburb of Aurora on July 20. A midnight showing of the Batman movie "The Dark Knight Rises" had just begun.

Police say Holmes, now 25, started stockpiling weapons, ammunition, explosives and body armor in the spring of 2011. He was a first-year student in a Ph.D. neuroscience program at the University of Colorado, Denver, but he failed a year-end exam and withdrew in June 2011, authorities have said. The shootings came six weeks later.

Federal authorities have said Holmes entered the theater with a ticket and is believed to have propped open a door, slipped out to his car and returned with his weapons. Police arrested him outside the theater shortly after the shootings ended.

Holmes graduated in 2006 from Westview High School in San Diego.