US President Barack Obama has told victims of the attack at a Batman film screening in Aurora, Colorado, that the whole country is thinking of them.
Mr Obama met survivors and families of the dead when he visited the University of Colorado Hospital in Aurora.
He said he shared hugs and tears and vowed that "out of darkness a brighter day is going to come".
James Holmes, 24, has been arrested in connection with the attack, which killed 12 and injured 58.
Mr Holmes is alleged to have opened fire during a packed midnight screening of The Dark Knight Rises before being detained outside the cinema.
He is currently being held in solitary confinement for his own safety and is reported to be not co-operating.
Aurora Police Chief Dan Oates said Mr Holmes had "lawyered up" and is not talking.