ST. LOUIS (AP) -- Matthew Quain still struggles to piece together what happened after a trip to the grocery store nearly turned deadly. He remembers a group of loitering young people, a dimly lit street - then nothing. The next thing he knew he was waking up with blood pouring out of his head. The 51-year-old pizza kitchen worker's surreal experience happened just before midnight earlier this year, when he became another victim of what is generally known as "Knockout King" or simply "Knock Out," a so-called game of unprovoked violence that targets random victims.