On a summer morning in 2007, a woman was working in the printing shop she owned in a suburban strip mall. Suddenly, she heard a loud banging noise coming from somewhere above her. She stopped the printer she was working on so she could hear better, and the sound kept coming – BANG, BANG, BANG. It was like metal drawers opening and slamming shut. She was about to go outside to see what was happening, but she stopped and just started laughing. Her friend who owned the business on the second floor right above her had a habit of rearranging his office, so the banging was probably file cabinets getting moved around. As a joke, she shouted up through the ceiling, “Keep it down, I’m working!” And then she restarted the printer. But about an hour and half later, she heard another loud noise. This time, it was the wail of sirens as police cars raced into the parking lot. The woman would soon find out that the noises she had heard earlier were not her upstairs neighbor rearranging furniture. Instead, it was the sound of one of the most violent crimes to hit this safe, quiet suburb in years.