CHICAGO (CBS) -- According to dispatch recordings, a ShotSpotter sensor alerted police to the shooting that killed Chicago Police Officer Luis Huesca nearly 5 minutes before the first 911 caller early Sunday morning. Mayor Brandon Johnson on Monday was asked repeatedly about this revelation and his plan to scrap ShotSpotter technology. The first sign that Officer Huesca was in trouble came in at 2:53 a.m. Sunday, in the form of a ShotSpotter alert for four rounds fired at 5501 S. Kedzie Ave. It was not for another 4 minutes and 50 seconds that a 911 caller picked up the phone,...