CENTENNIAL, Colo. — Attorneys for the suspect in the Colorado movie theater shootings said Thursday their client is mentally ill and that they need more time to assess the nature of his illness.

James Holmes' lawyers made the disclosure at a court hearing in suburban Denver where news media organizations asked a judge to unseal documents in the case.

Holmes, a 24-year-old former Ph.D. student at the University of Colorado, Denver, had the familiar, dazed demeanor that he had in previous court appearances.

Holmes is accused of going on a July 20 shooting rampage at a midnight showing of the latest Batman movie in Aurora, killing 12 people and injuring 58 others.

Defense attorney Daniel King made the revelation about Holmes' illness as he argued that the defense needs more information from prosecutors and investigators to assess their client.

"We cannot begin to assess the nature and the depth of Mr. Holmes' mental illness until we receive full disclosure," he said.

King said Holmes sought out university psychiatrist Lynne Fenton for help. A hearing was scheduled for Aug. 16 to establish whether there was a doctor-patient relationship between them.

There were fewer victims and family members in the courtroom Thursday than at earlier hearings. Several spectators appeared mesmerized by the sight of Holmes, unable to take their eyes off him.

Mental illness "doesn't give him the right to do what he did," Chris Townsond, who escaped the shooting unharmed, said after the hearing. "I don't care how mentally damaged he is."

Analysts expect the case to be dominated by arguments over the defendant's sanity, and Thursday's statement by the defense was the strongest confirmation so far that mental illness will be a key issue.

A court document previously revealed that Holmes was seeing the psychiatrist for unknown reasons.

Holmes' public defenders could argue he is not mentally competent to stand trial.

It was the argument used for Jared Loughner, who pleaded guilty this week to a 2011 shooting rampage in Arizona that killed six people and wounded 13 others, including then-Rep. Gabrielle Giffords.

If Holmes goes to trial and is convicted, his attorneys can try to stave off a possible death penalty by arguing he is mentally ill. Prosecutors will decide whether to seek the death penalty in the coming weeks.

The Associated Press and 20 other news organizations also asked Chief District Judge William Sylvester to scale back a gag order that bars the university from releasing details about Holmes.

Sylvester had said in issuing the order that he wanted to protect the county's investigation. But even Aurora officials have cited the gag order in declining to speak about the city's response to the shootings.

News media attorney Steven D. Zansberg said state law allows judges to issue gag orders barring prosecutors and law enforcement from commenting, but not agencies outside of the investigation, such as the university.

King opposed the news media motion, saying the gag order ensures fairness. Prosecutor Karen Pearson said she had filed her own argument on the issue in court – and that it is sealed.

Sylvester said he would rule on the matter by Monday. He did not say when he would respond to the news media's request to unseal the court documents.

Those documents include the case file, which makes it impossible for observers to understand prosecution and defense arguments on motions that are referenced by number only.

Those types of documents can be an important source of information for the public and can shed light on how police say Holmes prepared for the shooting and rigged his apartment with explosives.

Gregory Moore, editor of The Denver Post, said before the hearing that the news organizations are trying to perform their watchdog role, making sure the investigation is being conducted openly and fairly.

In Colorado, this type of legal battle has been seen before, including the 2003 case of Los Angeles Lakers player Kobe Bryant who faced sexual assault charges in Vail.

It took a news media challenge to unseal an affidavit in which police laid out their case for an arrest. Bryant maintained his innocence, and prosecutors dropped the case in 2005.

PHOTOS: HOLMES IN COURT
Loading Slideshow...
  • James E. Holmes

    James E. Holmes, left, appears in Arapahoe County District Court, with defense attorney Tamara Brady, right, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting on Friday, July 20, in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • James E. Holmes, Tamara Brady

    People in the courtroom listen to the court hearing of James E. Holmes in Arapahoe County District Court Monday, July 23, 2012, in Centennial, Colo. Holmes is accused of killing 12 and wounding 58 in a shooting rampage in a Colorado theater on Friday, July 20. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • James E. Holmes

    James E. Holmes appears in Arapahoe County District Court, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting last Friday in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • In this image taken from video provided by KUSA.com, James Holmes, left, the suspected gunman in Friday's Colorado theater massacre, makes his first appearance in court with his attorney Tamara Brady in Centennial, Colo. on Monday, July 23, 2012. (AP Photo/KUSA.com)

  • Carol Chambers

    Carol Chambers, district attorney for the 18th Judicial District, speaks during a media availability after a court appearance by James Holmes at the Arapahoe County Courthouse, Monday, July 23, 2012, in Centennial, Colo. Twelve people were killed and dozens were injured in a shooting attack early Friday at a packed theater during a showing of the Batman movie, "The Dark Knight Rises." Police have identified the suspected shooter as Holmes, 24. (AP Photo/Alex Brandon)

  • James E. Holmes, Tamara Brady

    James E. Holmes, center, appears in Arapahoe County District Court, with public defenders Tamara Brady, right, and Daniel King Monday, July 23, 2012, in Centennial, Colo. Holmes is accused of killing 12 and wounding 58 in a shooting rampage in a movie theater on Friday, July 20 in Aurora, Colo. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • James E. Holmes

    James E. Holmes appears in Arapahoe County District Court, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting Friday, July 20, in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • David Sanchez

    David Sanchez, whose son-in-law was critically wounded, speaks after a court appearance by shooting suspect James Holmes at the Arapahoe County Courthouse, Monday, July 23, 2012, in Centennial, Colo. Twelve people were killed and dozens were injured in the shooting attack early Friday at an Aurora, Colo., theater during a showing of the Batman movie, "The Dark Knight Rises." (AP Photo/Alex Brandon)

  • Family members of a victim from last week's theater shooting in Aurora, Colo., link hands as they arrive for a court appearance by shooting suspect James Holmes at the Arapahoe County Courthouse, Monday, July 23, 2012, in Centennial, Colo. Twelve people were killed and dozens were injured in the shooting attack early Friday at the packed theater during a showing of the Batman movie, "The Dark Knight Rises." (AP Photo/Alex Brandon)

  • A woman, third from left, is led to the courtroom where James Holmes appears in Arapahoe County District Court, Monday, July 23, 2012, in Centennial, Colo. Holmes is the suspect in the mass shooting last Friday in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Barry Gutierrez)

  • Anggiat Situmeang,

    Anggiat Situmeang, center, who suffered an injury in last week's theater shooting in Aurora, Colo., is helped inside to see a court appearance by alleged shooter James Holmes, at the Arapahoe County Courthouse Monday, July 23, 2012, in Centennial, Colo. (AP Photo/Alex Brandon)

  • James E. Holmes

    Assistant District attorney Karen Pearson speaks at a hearing for James E. Holmes in Arapahoe County District Court, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting last Friday in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • James E. Holmes

    James E. Holmes appears in Arapahoe County District Court, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting last Friday in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • James E. Holmes

    James E. Holmes appears in Arapahoe County District Court, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting last Friday in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • James E. Holmes

    James E. Holmes, left, appears in Arapahoe County District Court, with defense attorney Tamara Brady, right, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting on Friday, July 20, in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Denver Post, RJ Sangosti, Pool)

  • James E. Holmes

    District Court Judge William Blair Sylvester speaks as James E. Holmes appears in Arapahoe County District Court, Monday, July 23, 2012, in Centennial, Colo. Holmes is being held on suspicion of first-degree murder, and could also face additional counts of aggravated assault and weapons violations stemming from a mass shooting last Friday in a movie theater in Aurora, Colo., that killed 12 and injured dozens of others. (AP Photo/Denver Post, RJ Sangosti, Pool)