Jimmie Lewis, a burly, gregarious bartender, was walking home one night in September 2013 when he arrived at an intersection along Irving Park Road near Pulaski Road around the same time as off-duty Detective Hector Matias, who was driving his SUV. Each man waved the other through the intersection, then exchanged words. Matias, according to Lewis, grew irate, got out of his SUV and rushed at Lewis, who started taking off his backpack so he could defend himself.