I suppose this wasn't technically martial law, but it seemed like martial law to most of us. What's the difference? Martial Law is an interesting topic. It's not specifically allowed by the U.S. Constitution, so I suppose the legal absolutists will scream about it even in situations like this where it makes absolute sense - you just can't have civilian gawkers in the way of a possible shootout.

http://constitution.findlaw.com/article2/annotation09.html has some interesting comments, as does Wikipedia.

-Joe-