The judge in the Colorado theater shooting case could delay the trial yet again after defense attorneys said Monday they need more time due to medical emergencies involving members of their team.

James Holmes' defense attorneys said at a hearing that the medical problems, involving an attorney and an investigator, have complicated their review of a massive amount of evidence and preparations for the long-awaited trial, which has been postponed five times.

Jury selection is scheduled to start Jan. 20.

Attorneys discussed the medical issues privately with Judge Carlos A. Samour Jr. for nearly 30 minutes but did not disclose them in court.

"We're trying to jam all this work into a small amount of time at the end of this proceeding that has lasted more than two years," defense attorney Daniel King told the judge.

Holmes pleaded not guilty by reason of insanity to charges of killing 12 people and injuring 70 in the 2012 attack at a Denver-area theater. Prosecutors are seeking the death penalty.

In court filings last week, defense attorneys had asked for a two-to-three month delay to review evidence that includes 85,000 pages of documents, 366 CDs, 282 DVDs and other materials in computer memory drives.

King said Monday that expert witnesses are still studying the material, namely a sanity evaluation that includes more than 20 hours of interviews with Holmes and 5,000 pages of documents from the state mental hospital where it took place.

Prosecutors and some of the victims have said they oppose any further delay.

Jury selection alone is expected to last five months, with Samour sending summonses to 9,000 prospective jurors.