As the OP doesn't have a laser then you should be safe in assuming that no one knows about his interest in the "hobby".
As such, the question of just WHO is trying to get the attention of a young male by avoiding or without using any of the traditional methods of communication. To be using such a powerful device without leaving any trace just to be sure that you get noticed ! In just the kind of way to be un-traceable by any member of the authorities after the fact.
And to try it more than once over a fairly long period of time means that they think it must be less likely that trouble will develop from doing it again...BIG WARNING... if the timeframe between occurences shortens then the suspect is getting bolder and possibly more desparate for attention. This is a bad thing ! Stay aware of your surroundings.
A lot of "troubled" individuals start off with seemingly harmless things that only serve to bolster their courage to do more severe and flagrant things. Like testing the waters before going in. First just a toe, then more toes, then after a while the whole body is completely involved.
Sounds to me like this laser is at the "then more toes" stage now.
Prevent it from going any further. Raise awareness with all neighbors and file some form of written record with the local police.
Better safe than sorry.