Victims of the Colorado theatre shooting and their families have questioned whether the focus of the trial will be on the alleged gunman's mental health rather than the killings themselves.
Defence lawyers for James Holmes have disclosed their belief that the 24-year-old shooting suspect is mentally ill.
However, Shane Medek, whose 23-year-old sister Micayla Medek died in the July 20 incident, said: "They keep talking about fairness for him. It's like they're babying this dude."
Holmes is accused of opening fire in a movie theatre, killing 12 people and injuring 58. His lawyers disclosed their belief on Thursday during a court hearing that he suffers from a mental illness when nearly two dozen news organisations asked a judge to unseal case documents.
Defence attorney Daniel King argued that the seal and a sweeping gag order ensure fairness.
Analysts expect the case to be dominated by arguments over Holmes' sanity and the defence's revelation was the strongest confirmation so far that mental illness will be a key issue. A court document previously revealed that Holmes was seeing a school psychiatrist for unknown reasons.
Holmes, a former PhD student at the University of Colorado, Denver, sat during the hearing with the dazed expression that he had in two previous court appearances.
"It doesn't give him the right to do what he did," said Chris Townsond, who attended the court hearing with a wounded victim. "I don't care how mentally damaged he is."
King said Holmes sought out university psychiatrist Lynne Fenton for help weeks before the shooting. A hearing was scheduled for August 16 to establish they had a doctor-patient relationship.