Twelve people walked into a Colorado movie theater late one July night, expecting to enjoy a special midnight screening of the Batman film, "The Dark Knight Rises."

They didn't walk out.

Their deaths - and injuries to dozens of others - came after a man dressed head to toe in protective tactical gear sprayed the Century 16 theater in Aurora with bullets from an AR-15 rifle, a 12-gauge shotgun and a .40-caliber pistol, weapons police discovered at the scene.

On Monday, many grisly details of what happened could be presented in a Colorado court at a preliminary hearing for the shooting suspect, James Holmes.

Now 25, Holmes faces 166 charges, including murder, attempted murder and weapons offenses, tied to the July 20 rampage.

Bits and pieces emerged from police and witnesses shortly after the massacre. One was that Holmes had colored his hair red and told police he was "the Joker," one of Batman's archenemies, according to a federal law enforcement source with detailed knowledge of the investigation.

But much information has been kept under wraps, especially after Arapahoe County District Judge William Sylvester issued a gag order to prevent defense lawyers, prosecutors and law enforcement agencies from disclosing certain information to the media.

That could change after this week's hearing, which is expected to last several days.