Attorneys for a Florida man accused of killing a couple and chewing the husband’s face attacked the constitutionality of the state’s laws governing insanity defenses, arguing it wrongly places the burden of proof on defendants instead of prosecutors.

Austin Harrouff, 22, has said he was fleeing a demon-like figure when he ran to a home and attacked the couple living there, spitting out a piece of flesh when deputies arrived and were finally able to subdue him.