He thinks he's in a John Wayne film, where a guy with a bright T-shirt that says 'TERRORIST' across it will announce his intentions, before opening fire with an AK-47 in a public place. He will then draw his Smith & Wesson, and put the criminal down with one well-placed shot.

In the real world, this is, of course, laughable. Even people with guns don't fight back against armed gunmen, for two reasons.

1. Most of the time, you have no idea who the armed gunman is.

2. You are very likely to be mistaken for the gunman, and shot and killed by the police.