BOULDER, Colo. (AP) -- A Colorado man suspected of hiding in the tank of a portable toilet at a Boulder yoga festival and spying on women in other bathrooms is asking a judge to change his plea to not guilty by reason of insanity.

The Boulder Daily Camera reports 31-year-old Luke Chrisco is facing eight felony counts of second-degree burglary as well as two misdemeanor counts of unlawful sexual contact and criminal invasion of privacy.

Chrisco was arrested after a woman using a portable toilet at the festival 2011 noticed something moving in the tank and then saw a feces-stained man emerge and run away. Police also think he used peep holes in bathrooms in several Boulder businesses and on the University of Colorado campus.