A registered sex offender in Minneapolis has pleaded guilty to producing or attempting to produce child sexual assault material. Christopher Allan Amelsberg, 36, pleaded guilty on Monday, according to the Department of Justice — his sentencing date has not yet been set. During this time, Amelsberg was already a registered sex offender for a prior conviction of possessing CSAM. “For years, and while being a registered sex offender, Christopher Amelsberg sexually exploited at least a dozen children from his home in Minneapolis,” said FBI Minneapolis Field Office Special Agent in Charge Christopher D. Dotson. “Even after a previous state conviction for possessing child sexual abuse material, this defendant did not learn his lesson.