It will be two months tomorrow since Michael Brown was shot to death on the streets of a St. Louis suburb, and we still don't know with any degree of certainty what happened there.

But we do know that last night, another young black man was shot and killed by a police officer in St. Louis, reigniting tensions in that city and threatening to set off another round of confrontation between protestors and law enforcement.

However, this latest case looks very different from the Brown case, at least at the outset.

In last night's shooting, Vonderrit Myers Jr., 18, is alleged by police to have fired a weapon at a St. Louis officer who then returned fire, killing Myers. Police say the suspect's weapon, a stolen Ruger handgun, was recovered at the scene and had fired several rounds before jamming. Three spent bullets from the gun were reportedly found at the scene. And Myers was out on bail on a previous gun charge.

Myer's family continues to insist that he was unarmed and that police officers mistook a sandwich in his hand for a weapon. If so, the Ruger and other evidence had to have been planted as part of a coverup, but at this point that does not at all seem to be the most likely explanation. An investigation is required, but sometimes, law enforcement officers are simply given no choice but to respond with deadly force.

That said, it's also not hard to understand why suspicions run so high.

There's the troubling case of the SWAT raid in Habersham County that went badly awry. There's an equally troubling case out of East Dublin, Ga., involving another SWAT raid that killed an apparently innocent man in his home. Officials in New York City are investigating this potential case of an officer abusing his authority. And this. And this. And this.

And this one of course:

The spread of smart phones and surveillance cameras is giving the public a peek into incidents of police abuse-of-power that had not previously been available. In some of the cases cited above, it's conceivable that they would have been ignored or dismissed without video evidence. I also think it's pretty clear that such video documentation is increasing public awareness that sometimes, police just get it wrong, out of incompetence or in other cases out of a distorted sense of power.

Of course, that same technology can also be used to vindicate an officer, as it was here as well. And after watching the video of the tragic mistaken shooting at WalMart in Ohio, I'd say that I can understand why officers reacted as they did, and also why others criticized them for reacting too quickly. (The grand jury in that case chose not to indict the officers).

It's not an easy balance, nor will it ever be, but technology is changing the environment profoundly. Every police agency in the country ought to be buying body cameras for their officers, both as a reminder to those officers that they too are accountable, and for their own protection should they be forced to take justified lethal action in the line of duty.