From left: Chicago Police Department Lt. Mike Kapustianyk, Ald. Ed Burke (14) and Ald. Emma Mitts speak during a City Council public safety committee meeting on Friday.

City and police officials on Friday had scant answers for aldermen who asked for data and research explaining how Mayor Lori Lightfoot’s proposal to permanently change the city’s curfew for minors from 11 p.m. to 10 p.m. would help curb violence.