The Officer was carring a 40 Cal. more umph than the 9mm. (around here almost nobody carries the 9mm anymore. It's all 40's or 45's. shotguns aren't real good in crowded situations less you're after the whole crowd. Depends on what you're trying to accomplish with a shotgun. THERE IS NOTHING as DISTINCTIVE as A SHOTGUN racking a Shell into the chamber. You WILL get instant attention from everyone. I don't know about slowing the man down,, Officer hit dead center mass with 40 cal. I'd say the guy was just really lucky (unfortunately) he didn't die. | 
Kudo's to a young Officer showing what he is made of
