A statement from the actress reads: "My heart aches and breaks for the lives taken and altered by this unfathomably senseless act. I am at a loss for words how to express my sorrow. My thoughts and prayers are with the victims and their families."
Director Christopher Nolan, actor Christian Bale and composer Hans Zimmer have also expressed their sympathy for the families and the victims.
Twelve people died and dozens more were injured early last Friday morning when James Holmes, 24, entered an Aurora cinema near Denver in full combat gear and opened fire on filmgoers there to watch a midnight screening.