There is more at play here than just going over the line. The area under discussion is what about 4 feet? No, it is a racial thing. Racial + asshole= Problems. Sorry for that but it is what it is. IMO, this had nothing to do with a kid’s error, it was just the fuse on a long standing feud.
I actually could see it being more of a fear thing, not “racism” between races related, rather stereotype “racism”.
But, what are most black 12 year olds doing? Stereotypically, not being industrious, entrepreneurial.
And it looks like possibly an older neighborhood.
So if you have an older person in that house, a bunch of “yutes” climbing all over, making noise (from that person’s perspective), could have all been fear related.
Feud could also come into play.