In this Friday, Oct. 26, 2018, photo, Philadelphia Police Sgt. John Ross discusses the Police 9th District's juvenile holding cell in Philadelphia. Bloomberg Philanthropies announced the winners Monday of the U.S. Mayors Challenge that asked cities to develop innovative solutions to their biggest problems that other cities could copy. Philadelphia plans to build a juvenile justice hub designed to make contact with police less traumatic, keep more children out of the criminal justice system and connect at-risk juveniles with intervention services at a crisis point that could change their lives. (AP Photo/Matt Rourke)