Most gunfights are “come as you are” events. There’s no way to fully predict what can happen and what you’ll need to succeed. What we know for sure is that what you bring with you is all you’ll have to finish the fight.
I’m not sure if Jeff Chudwin is the person who originally penned the phrase “Fights are a come as you are event.” I have often heard John Farnam mention the phrase on his lessons learned site as well. If anyone knows who coined it please mention it in the comments. Regardless, I have always appreciated that phrase because it expresses your primary issue while preparing for duty.
Jeff’s article describes a typical loadout that an officer should have to be prepared in today’s world.
Update: Interesting comments about this article at Phil’s Blog.