On the night of March 5, she was out on Fifth Avenue near a viaduct a couple blocks east of Cicero Avenue, an area of the Lawndale neighborhood she called the “Stroll” that is known by police for prostitution. The woman did not admit she was working as a prostitute that night. But at the time, she said, she was with a man — whom she referred to as her boyfriend — who was “watching out for her” and “acting as her security” when a marked Chicago police vehicle pulled up.