From then on, I tried to make it a habit to suppress my excitement at such moments. Indeed, I strove for an inverse correlation between my internal excitement and any outward expressions of it. On those occasions when I was able to dialogue with some guy, I inhibited the temptation to let him know when I'd caught him in a lie so as to catch him in many more as the conversation progressed.
Not surprisingly, I didn't end up scaring off as many bad guys...got more of them to talk with me...and generally had an easier time getting them in the backseat (save for those taciturn dirtbags that seem to get under most of our skins).
There will always be those cretins that'll take flight at the sight of a uniform or black and white. But there will also be those other reptiles that try to lay low and blend in with the scenery in the hopes that you will pass them by. They're the ones you can sometimes sneak up on.
Now, maybe you've always been able to take things in stride, and never tilt your hand. If that's the case, my hat's off to you.
But if not, think about getting in touch with your feminine side. Be a little sneaky and develop some subtlety when you're out doing recon. Resist that temptation to telegraph your recognition. Drive on by, then double back around. Maybe coordinate some units to contain the guy before he takes flight.