DENVER — A mental hospital says the sanity evaluation of Colorado theater shooting suspect James Holmes will take until mid-September, nearly seven weeks longer than the judge wanted.

Judge Carlos T. Samour Jr. set a July 31 deadline for the Colorado Mental Health Institute to finish the evaluation and submit a report. In a letter made public Thursday, the hospital asked for an extension until Sept. 16.

The hospital cited the volume of documents the psychiatrist in charge has to review before starting the interviews and in-person testing of Holmes. Attorneys have said the evidence in the case takes up nearly 40,000 pages.

Samour scheduled a hearing for Tuesday to discuss how the delay will affect the schedule for hearings and the trial. Hearings were scheduled to take up all of August and parts of November and December. The trial was set to start in February.

Holmes is accused of killing 12 people and injuring 70 at a suburban Denver movie theater in July. Prosecutors are seeking the death penalty.

Holmes has pleaded not guilty by reason of insanity. The trial cannot begin until the sanity evaluation is completed.