I suppose you could walk up and ask the kid to point the gun at you so you can examine the bore, but with some realistic-looking replicas that is the ONLY way you could tell the difference (with the gun being in someone else's hand).

Now, let's pretend you're a cop, you get a call from dispatch, you drive around and see the kid with the gun, it looks real, then instead of complying with your verbal command he points it at you from (does it say how far?) okay pick 20 yards. That's 60'. Even in broad daylight i challenge you to determine the caliber of the gun, or positively ID it as a toy, from that distance.

A 15 year old kid generally wouldn't be cruising brandishing a realistic looking gun unless he was impaired (by the way, that was some story, Headbanger - how close you came to a terrible life-altering event) or up to no good. for all we know, he was on his way to rob a pharmacy. Or maybe just to play air-soft with a buddy. Either way, i assert the likelihood that the LEO acted appropriately, and nobody involved - and i mean nobody - is going to come through this unchanged.

What a departure from when i used to roam the cul-de-sac with my six shooters trailing popped cap rolls out both holsters. Or hit entire rolls of caps with a hammer for the big BANG. Oh, for the good old days...

There are at least 2 lessons here for parents.
1. Toy guns have to ALWAYS have the dopy looking orange insert. It is a crime to modify those guns to remove the orange and make it look more realistic in more than a few states, did you know?
2. If your kid wants to play with toy guns, you must impart some safe handling knowledge - ie., don't point the blasted thing at people, especially COPS. Its a perfect time to start the basic gun safety rules on them.