CENTENNIAL, Colorado — The judge overseeing the Colorado cinema massacre trial said Thursday he wants opening statements in the much-delayed case against gunman James Holmes to begin on April 21.

Lawyers for both sides are questioning potential jurors ahead of the start of the trial, at which Holmes faces the death penalty if convicted of murder and attempted murder for fatally shooting 12 moviegoers and wounding dozens more in a Denver-area theater during a screening of a “Batman” film in July 2012.

“We hope to have openings on April 21,” Arapahoe County District Court Judge Carlos Samour told one prospective juror.

He had previously said only that both sides should be ready to make preliminary remarks in late spring.

Potential jurors are being questioned about their views on the death penalty and the use of insanity defenses in murder cases, among other issues.

Holmes, who was in court dressed in a gray shirt and gray slacks and tethered to the floor, appeared more animated than he has in the past, reading documents and writing notes.

His public defenders concede the 27-year-old former neuroscience graduate student was the sole gunman, but say he is not guilty by reason of insanity.

The California native’s trial has been delayed several times, mostly by legal wrangles over two court-ordered sanity exams he has undergone since his arrest.