Christian Bale has visited survivors of the shooting at a US cinema showing his new Batman movie The Dark Knight Rises.
The actor, who plays the caped crusader, visited with little advance warning and also stopped by a makeshift memorial to victims near the Colorado cinema that was showing the film when the gunfire erupted.
Carey Rottman, one of the 58 people injured in Friday's shooting, posted two photos of himself with Christian on his Facebook page.
Janie Bowman-Hayes, assistant vice president of surgical services at sister hospital Swedish Medical Centre, said she and co-workers were attending a luncheon at The Medical Centre of Aurora to thank staff who tended to victims. "When we got there, then we found out he was there," she said.
Christian, dressed casually in a black T-shirt and jeans, thanked the staff, shook hands and agreed to have his photo taken with employees, Ms Bowman-Hayes said.
"He just said he wanted to come to thank all of us because he has been thinking about this. He knows the whole world has been thinking about this," she said. "He took it upon himself to come and thank us."
An online campaign had urged the actor to visit survivors of the shooting.
Christian, joined by his wife Sibi Blazic, also stopped by a growing memorial near the cinema and walked among the 12 crosses erected for each of the slain victims. Many people there did not appear to realise who he was or chose to leave him alone.
A Warner Bros spokeswoman told The Denver Post that the star was representing himself, not the film studio.