Sometimes you need a cop in your movie who will deliver big chunks of expository dialog to the main character in order to keep the plot going. Folks often think of James Remar when it comes to casting that cop. Occasionally he might play a military guy, but the purpose of the role is always the same: human info dump.
Here's James Remar mocking Blade with another officer in Blade: Trinity. And you thought Ryan Reynolds was the best part of that movie? THINK AGAIN.
And here's James Remar as Uptight Agent giving a briefing in the fine film 2 Fast 2 Furious. "Use extreme caution, this man has been known to use rats and blow torches to torture people. Yes, rats and blow torches at the same time."
Here's James Remar playing Expository Cop on CSI: Miami. Sometimes your episode gets so fucked up that you have to bring in somebody to help explain the plot to the main characters. James Remar is that somebody.