A man sits on a curb holding a 2 ½-inch knife blade to his throat. His girlfriend just broke up with him, and he’s unsure of where he’s going to live. He’s distraught, but he keeps to himself before someone sees him and calls 911. Two Chicago police officers, a man and a woman, soon arrive at the imaginary intersection of Jimenez and Wortham streets, where the female officer calmly tells him ...