MILWAUKEE -

Four Milwaukee police officers accused of illegal strip searches have pleaded not guilty to charges.

Prosecutors said Officer Michael Vagnini conducted body cavity searches and the other officers didn't stop him. Vagnini is facing 25 charges, including sexual assault. The other three officers, Jeffrey Dollhopf, Brian Kozelek and Jacob Knight, are charged with misconduct in office and violating the strip search law.

The four officers were in Milwaukee County Circuit Court Thursday to enter their pleas. Kozelek's attorney, Patrick Brennan, argued there's no proof the defendant knew Vagnini didn't have authorization for the searches.

WISN-TV reported District Attorney John Chisholm argued simply being present and not objecting is enough to support criminal charges.

The officers are expected back in court for a pretrial hearing next month