Also, I doubt the phone call person and door knocker are the same person and I doubt EITHER one of them is the TEENAGER next door (by the way, am I the only one here who knew ding dong ditch by a much less politically correct term).
Knocking and running is a grade school prank. I remember lots of kids doing it in grade school, and I think I even did it myself once. However no one was doing that by the time I was a teenager, it is just such a lame prank.
That makes me clear the teenager in question based on the fact that a teenager doesn't fit the psychological profile of who would do something like that. (My guess would be a boy of about 11, he is probably skinny, as fat kids can't run away reliably. Anyone on the street fit that description?) In fact, it is probably a trio of boys around that age (boys tend to get in trouble in groups of three).
As for the phone calling, that is the domain of 13-15 year old boys, although I severely doubt they would target (or even have) the telephone number of their elderly neighbor. Why hang up on grandma jones when you could hang up on Samantha from homeroom? Is there any talking with these phone calls or are they just hangups or beeping?