Defendant James Holmes had been scheduled go on trial in October, but District Judge Carlos A. Samour Jr. ordered a delay because a doctor requested more time to complete Holmes' second sanity evaluation.
Samour announced the new date Wednesday.
Separately, Samour ordered prosecutors to clarify a statement they made to victims, saying it could be misinterpreted as telling them there was no need to speak to defense lawyers, even if they had something to tell them.
Holmes, 26, a former graduate student in neuroscience, pleaded not guilty by reason of insanity to charges of killing 12 people and injuring 70 in the July 20, 2012, attack.
Holmes' lawyers acknowledge he was the shooter but argue he was in the grips of a psychotic episode.
Prosecutors are seeking the death penalty.
More than 400 people were watching a midnight showing of "The Dark Knight Rises" in the theater in the Denver suburb of Aurora at the time.
Holmes underwent a mandatory sanity evaluation last year. The key findings haven't been released, but prosecutors charged that the doctor who conducted it was biased.
After a closed-door hearing in January, Samour concluded that the first evaluation was flawed and ordered a new one.
This is Holmes' fourth trial date. The first date, in August 2013, was canceled after prosecutors said they would seek the death penalty, raising numerous issues that had to be resolved before trial. The second, in February of this year, was scratched after prosecutors asked for the second sanity evaluation.
The third was Oct. 14, which the judge vacated last week after the doctor requested an extension.
Samour ordered the Arapahoe County District Attorney's Office to clarify a May 8 email that one prosecutor sent to victims, telling them they could express their opinions through the DA's office as well as — or better than — they could by speaking to the defense.
The judge rejected defense attorneys' allegation that this was improper interference by prosecutors, but he said the email should have been worded better and must be clarified.
Prosecutors wanted Samour to punish prosecutors by ruling out the death penalty, prohibiting victims from testifying at the punishment phase of the trial if Holmes is convicted or by disqualifying the Arapahoe County DA's office from the case.
Samour also rejected a defense request to see all the emails and letters prosecutors sent to victims.
In a letter to Samour released Thursday, the doctor who will conduct the second evaluation said he wants to videotape the examination because it will provide a more accurate and thorough record than handwritten notes.
The doctor, whose name has not been released, also said the videotape could be destroyed after his report is complete.
Holmes' lawyers don't want the doctor to videotape the examination, arguing state law doesn't authorize it and that it could "interfere with the integrity" of the exam.
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