(Reuters) - The judge in the trial of accused Colorado theater gunman James Holmes said in a court filing on Friday that he expects the initial jury pool could include 3,500 people, a figure a legal observer called unusually large and a reflection of the high-profile nature of the case.
Holmes is accused of killing 12 moviegoers last summer in a suburb of Denver.
Arapahoe County District Judge Carlos Samour Jr. revealed the potential size of the jury pool in a ruling that granted the defense's request to have potential jurors complete a written questionnaire.
"The court anticipates that as many as 3,500 individuals may respond to jury summonses issued in this case," Samour wrote in the decision filed on Friday.
Samour granted the request for a questionnaire, saying it "will be helpful and will save time and effort during the jury selection process."
Holmes, 25, is charged with multiple counts of first-degree murder and attempted murder in the July 2012 shooting spree in a suburban Denver multiplex during a midnight screening of the Batman film "The Dark Knight Rises." He could be sentenced to death if convicted.
The former University of Colorado-Denver graduate student earlier this month entered a plea of not guilty by reason of insanity, replacing a standard not-guilty plea entered in March on his behalf.
Stan Goldman, a professor at the Loyola Law School in Los Angeles, said in a phone interview that in the normal process of selecting a jury of 12 people, plus alternates, for a murder trial, courts often begin with a jury pool of less than 40 people.
He said there are a number of issues in the case, such as the proposed insanity defense, the multiple counts of murder and expectations for a lengthy trial, that could raise problems for potential jurors.
"You want to cast a pretty wide net to find out what people really feel," Goldman said.
The Aurora rampage ranks as one of the deadliest mass shootings in U.S. history, and along with the massacre of 20 children and six adults last December at Sandy Hook Elementary School in Connecticut, helped reignite a national debate over gun control.
In addition to the 12 moviegoers slain in the theater shooting, 58 people were wounded by gunfire and another 12 suffered various other injuries in the ensuing pandemonium.
(Reporting by Alex Dobuzinskis; Editing by Bill Trott)