(Reuters) - Lawyers for accused Colorado theater gunman James Holmes are questioning the constitutionality of the state's insanity defense law, court records released on Tuesday show, and raising the possibility that they may enter an insanity plea over his objections.

Public defenders for Holmes, 25, said in a filing that there is "significant uncertainty and confusion" in Colorado law surrounding an insanity defense in the context of a case where prosecutors are seeking capital punishment.