Accused Colorado gunman James Holmes has a "mental illness" and tried to get help before the shooting, his defence attorney said in court.
Mr Holmes' public defender Daniel King repeatedly made references to his client's unspecified mental illness, giving the first clear sign that his lawyers might be considering an insanity defence.
The 24-year-old former neuroscience graduate student at the University of Colorado faces 24 counts of first-degree murder and 116 counts of attempted murder.
Mr Holmes is accused of bursting into a midnight screening of "The Dark Knight Rises" in the Denver suburb of Aurora and opening fire in the crowded cinema, killing 12 people and wounding 58 others.
He appeared in court yesterday, during a hearing on media access to court files, wearing maroon prison clothes and shackled at his hands and ankles.
Mr Holmes seemed alert but disinterested in his third appearance in a Colorado courtroom since the 20 July mass shooting. He mostly stared straight ahead and did not talk to his lawyers.
Court papers filed by defence attorneys two weeks ago said Mr Holmes had been a patient of the medical director for student mental health services on campus before he filed paperwork to drop out of the competitive graduate programme.
That psychiatrist, Dr Lynne Fenton, reported Mr Holmes to a campus threat assessment team and a campus police officer over concerns about her patient, according to media reports.
The university has declined to comment on the reports but said it had hired a former federal prosecutor to probe its dealings with Mr Holmes.
As in many states, mental health care providers in Colorado must warn authorities of potential violent behaviour only when a patient has communicated a serious threat of imminent physical violence against a specific target.
Judge William Sylvester said he would consider a request by 20 media organisations to unseal and make public documents detailing the murder case against Mr Holmes, and would issue a written ruling later.
Mr Holmes is being held without bond and in solitary confinement at the Arapahoe County prison.
