DEDHAM, Mass. — Former Roman Catholic Cardinal Theodore McCarrick, the once-powerful American prelate who was expelled from the priesthood for sexual abuse, pleaded not guilty Friday to sexually assaulting a 16-year-old boy during a wedding reception in Massachusetts nearly 50 years ago.

McCarrick, 91, wore a mask and entered suburban Boston’s Dedham District Court hunched over a walker. “Shame on you!” a protester shouted.

He did not speak during the hearing, at which the court entered a not guilty plea on his behalf, set bail at $5,000, and ordered him to stay away from the victim and have no contact with minors.

McCarrick is the only U.S. Catholic cardinal, current or former, to ever be criminally charged with child sex crimes.