When a recent University of Chicago graduate was killed by a mugger near campus last year, police tracked the suspected gunman across town with the help of a high-tech array of 400 cameras that read license plates.
A month later, the cameras led police to a suspect who was about to enter the Dan Ryan Expressway after fatally shooting a man in Chinatown. And in February, a camera helped catch a 16-year-old boy suspected of gunning down a 15-year-old boy minutes earlier in Bronzeville.
