Hey CarmelHP, sorry it took me so long to get back, this big boy needed a nap!
Ok, please understand that everything is situational and VERY dependant on that situation. It's kind of like one of those "choose your adventure" books I used to read as a kid. If this happen you go here, if this happens then go here.
We'll start with the obvious, stop and ID the kid, ask him where they are going, where they have been. I am looking at his physical appearance (is he sweating heavy, are his shoes wet and grassy) see if those answers make sense.
If he says he's going home after playing guitar hero at a friends house, then call his parents to come pick him up (especially if he's a juvenile). If his ID puts him living at 32/Guilford and he can't come up with a real good reason for being there other that he was at a friends house but can't remember his name, we have problems.
Did we get any calls on him walking, or did I just come across him?
I think any reasonable person can see that there are too many variables to just spout off an answer to the question of "What next"
My short answer is check him out. Do I have reasonable suspicion that criminal activity is afoot? In one of the cases above yes I do. In the other, not really but I also have an obligation to the community and the parents/juvenile to make sure they get home safely. So in the other, assuming it is a juvenile (under 18) then they would be "detained" long enough for a parent to come get them and take responsibility for them. So even though no criminal activity is afoot, once again the Supreme Court has given us outlines when we may detain someone for a "community caretaker" function. This cleary fits that description.
I believe that yes, I do understand and practice good Terry stop techniques.
CarmelHP - if you are trolling for some Nazi like answer to get all huffy about, then you had better look elsewhere.
Good Explanation