A hearing scheduled yesterday for the man accused of killing 12 people and wounding 58 others in a Colorado cinema, was delayed after he was taken to hospital for an unspecified medical condition.
James Holmes was injured after he pounded his head against the walls and floor of his prison cell, a local television station, ABC7, reported.
His lawyer, Tamara Brady, gave few details about his condition, but said: "It's not as simple as a migraine."
Mr Holmes, a 24-year-old former neuroscience graduate student, is accused of opening fire inside a cinema in Denver during a screening of The Dark Knight Rises in July.
Police sources told another local television station, CBS4, that Mr Holmes had made multiple "half-hearted" suicide attempts over the past few days, including one in which he ran into a wall in his cell.