There's no excuse for initiating violence amid protests. All who have been caught doing so in Ferguson, Missouri, ought to be prosecuted, whether they are police officers or residents. When stores are looted and molotov cocktails thrown, it is common and just for law-enforcement officials to identify perpetrators once things have quieted down.

It is less common for officials to pore over video tapes looking for misbehavior among their own. Yet doing so is arguably more important to upholding law and order.

And there's already a lot of illustrative footage out of Ferguson.

CNN's Jake Tapper put together a short feature on the looting of immigrant-owned stores. As you can see in the video below, the faces of several perpetrators are exposed via surveillance cameras:

I'm confident in the ability of the U.S. justice system to prosecute crimes like that. But what about when an officer of the law is caught on video doing what, at the very minimum, appears to be a crime? Consider Missouri state law (emphasis added):

A person is guilty of assault in the third degree if he: attempts to physically injure another person or recklessly causes physical injury to another

negligently causes bodily injury to another with a deadly weapon

purposely threatens another person, causing that person to feel afraid that he is about to suffer serious physical injury

recklessly engages in conduct that creates a grave risk of death or serious physical injury to another person

intentionally engages in physical contact with another that the victim finds offensive or provocative, with knowledge that the victim will find it offensive or provocative, or

knowingly engages in offensive or provocative contact with an incapacitated person. (Mo. Ann. Stat. §565.070.)

Now watch this video footage of a police officer advancing on a member of the media—reportedly with a weapon drawn, although that isn't visible in the shot—and audibly threatening to "shell" the cameraman if he doesn't turn his light off immediately (presumably with a tear gas or smoke canister, although that isn't entirely clear):