Err, I have a problem with that
Yes I dont have any experience with arresting people, but I've always been taught that you never point a weapon at someone unless your willing to kill them. If someone points a gun your way, you would believe that too.
I would think that aiming a weapon at someone escalates the situation. I dont mean just brandishing, that I'd understand as your trying to reinforce your authority, but to put the muzzle in thier face as an unmistakeable threat.
Your forcing a choice on the target to fight, flee, or submit. 2 in 3 chance of getting a reaction you dont want.