During all your years on sentry duty, how often did you find yourself in situations where you needed to shoot someone? Do the police find themselves in that situation more frequently (or are they significantly more likely to)?

Also, in the event that you did, how far away was your nearest armed support? Sixty seconds? Less?

'Needed' might be the wrong word.

Three times in 2 3/4 years I had a weapon drawn, round in the chamber.

Twice I did not have a target. Once, I did but he obligingly put his hands up when ordered.

how far away was your nearest armed support? Sixty seconds? Less?

Depended on the sentry post, other factors. Sometimes right behind me. Other times minutes away, at best.

If your point is that police are more likely to encounter bad guys than a Marine guarding strategic assets .. maybe.

How does the police department owning a armored personnel carrier help a patrol officer at a traffic stop? How often does your average Mayberry police department encounter bad guys who can only be overcome by a SWAT team?

"How does the police department owning a armored personnel carrier help a patrol officer at a traffic stop?"

And how does the USN carrying nuclear weapons help you check passes at the gate?

That aside, yes, my suggestion was that the police are more likely to need the firepower than you were, and were more likely to have to get by on their own for longer before support turned up.

Supposedly most cops will go through their careers never drawing their weapons on duty. Don't know if it's true, but I've read it.

I've had 'most' cops beat by the time I was 21 and I wasn't even trying.