From www.talkingpointsmemo.com
A police officer needs to be able to respond to a call about a possible burglary, knowing he or she is going into a situation where they might find an actual burglar, who could be armed and might act in an unpredictable and lethal way. But they also need to be able to turn on a dime once it's clear it's not a burglar but the owner of the house, tired and coming home from a long trip. And on top of that, even though the cop was responding to help the owner of the home, the cop needs to be prepared for the fact the owner may be embarrassed or angry for being treated like a criminal in his own home. If that happens, the cop needs to be able to understand the reasonableness of the reaction and deescalate the situation -- not get into a macho pissing match which ends up getting decided in the favor of the cop because he has the handcuffs and the gun. (It's my strong sense that this is what happened in the Gates case.)
My brother was a police officer both in New York City and later in Suffolk County on Long Island. Being nine years his junior, I was naturally fascinated by his job and would pepper him with questions about what his job was like so as to share vicariously in what I saw as a super duper job.
The reality of it as Josh Marshall points out in his piece (which I suggest you read in its entirety) being a cop is like no other profession or job in America. 99.99% of us go to work every day anticipating that it will probably be just like yesterday as the next day will be like today. We plow through until the day finally comes when we can pack it in. The sameness is unrelenting.
But being a cop is living the flip side of "Groundhog Day". Today will never be the same as any other day past or future. It is a job which by its very nature is fraught with danger and the possibility of sudden violence or even death. The most routine traffic stop can quickly become a murder scene. And every cop knows this. The next time your driving and happen to pass a cop approaching a car he has pulled over take note of how his gun hand hovers above his weapon.
But I agree totally with Marshall that every police officer must balance his heightened sense of confrontation with the ability to ameliorate the situation once the facts are established and the danger level has been abated. It's not easy. Marshall is right. It's having to turn on a dime. I'm not sure that any human has the ability to control his or her adrenaline to that extent. Perhaps that's another defensive skill that should be taught these members of the thin blue line.