I need to know the law.

[Andail]

Well, it was the upper limit of 'kid' - he was like 19 or 20 or something. Old enough to know what he was doing, but young enough to suck at it.
As for the ski mask - I imagine it's not the first thing you think of when you're hanging upside down by a broken ankle in the middle of the night.

It doesn't need to be the first thing...he was apparently hanging there for quite some time. Sooner or later, it must have struck him as a good idea to remove this garment, seing how infinitely stupid it'd be to keep it on. It's after all a human being we're discussing, not a deer caught in a trap. I'm just arguing this because the picture of a perpetrator hanging upside down wearing a skimask is a comical element often found in urban myths...especially with the lawsuit follow-up.

EDIT (to keep on track):
In most countries, as a civilian you're not allowed to systematically survey or monitor another person. It'd most likely be regarded as stalking, even if you're only following or watching the person (during longer periods, of course).