Lawyers for James Holmes, the former graduate student accused of a shooting spree during a midnight showing of "The Dark Knight Rises" at a movie theater in Aurora, Colo., argued the law compels defendants to confess, in violation of the Fifth Amendment of the U.S. Constitution, The Denver Post reported.
Under the law, defendants who don't cooperate with an independent evaluation with a psychiatrist named by the court cannot use evidence of mental illness during the trial or in an effort to avoid the death penalty. Colorado District Court Judge Carlos Samour said prosecutors would be unable to rebut defense testimony without the independent evaluation.
The judge is expected to rule Friday on whether Holmes can plead insanity.
Holmes is charged with 166 counts of murder, attempted murder and other counts in the July 20, 2012, attack at the Century Aurora 16 movie theater. Twelve people died and 58 were wounded in the shooting spree.
A not guilty plea had been entered on Holmes' behalf in March when his attorneys declined to enter a plea for him. His attorneys said this month they would switch to an insanity defense.