Hundreds of mourners gathered in Aurora on Friday for a candle-lit vigil in remembrance of those who lost their lives in the Century 16 cinema in Aurora, Colorado.
Twelve people died and 58 were injured in the shooting during the midnight premiere of the latest Batman movie, The Dark Knight Rises. Thirty people are believed still to be in hospital and the condition of 11 is said to be critical.
"It's an act that defies description. Everyone I've talked to all day is filled with an anger that can't find focus," Colorado Governor John Hickenlooper told a press briefing.
Candles, flowers and written messages were left on the grass near the cinema as mourners tried to console one another and prayed for the victims.
"To all the innocent souls... This is for you. We will never forget. This is Aurora," read one note.
"Thoughts and prayers for everyone impacted by this tragedy," read another.
James Holmes, 24, entered the cinema wearing a gas mask and body armour. He threw gas canisters and began shooting at the audience, many of whom at first thought his actions might be a promotional stunt.
Holmes, believed to have been a student of the University of Colorado Medical School until June, was arrested in the cinema car park. He will appear before the Arapahoe County District Court in nearby Centennial, Colorado, at around 10:30 am local time (15.30 GMT) on Monday.
He was said to be armed with four weapons - a rifle, a shotgun, two pistols - when he started shooting. According to the police, Holmes bought 6,000 rounds of ammunition legally online within the past two months.
Bomb disposal teams detected complex booby-traps and heavy explosives in Holmes' home as experts moved cautiously to defuse the ammunition. Attempts to deactivate the explosives will resume on Saturday.
"I've personally never seen anything like what we've found in there," the BBC quoted Aurora police chief Dan Oates as saying.
The director of the movie, Christopher Nolan, expressed his grief over the incident.
"Nothing any of us can say could ever adequately express our feelings for the innocent victims of this appalling crime, but our thoughts are with them and their families," said Nolan in a statement.
Below are images from the candle-lit vigil held at Aurora for the victims: