This interests me, Loftearmen, thanks for sharing (although it's leading me to a slight thread derailing). I'm hardly qualified to comment on this arena, since I grew up in a neighborhood that was pretty much the classic upper-middle-class-privileged suburb and had every advantage.
But, my sister-in-law now teaches in a SD that's not "dangerous" by any means, but rather a poor-ish rural school, and she sees a (nonviolent) version of what you're describing. No problems with gangs or felons, just a bunch of unmotivated kids who basically don't see any point in "school" for any reason, and she believes that the parents are largely to blame.
She tells stories that are half-funny, half-awful (not in a "kids bringing guns to school" sense but in a "these kids are just waiting until they can legally drop out" sense); for example, she will see a kid sitting there just not working while she's giving a test.
She'll quietly walk over and ask (in her best calming, motherly whisper): "Hey, Student Name, why aren't you working on the problems?"
To which the kid will reply: "I ain't got a pencil." (as though that entirely excuses him from taking the test. Instead of asking to borrow a pencil, they'd rather just sit there and not even try. No concept of voluntarily taking a zero on the test being a "bad" thing, it's just something they have to sit through until they can leave school for the day)
Like I said, not exactly a violent horror story, but sad in a different way. When the parents don't set any expectation for kids to even try, I don't think any amount of increased school funding or great teachers will make up for that.
Surely, you can make a living in this country without being able to do geometry proofs and algebra. I'm not here to comment on whether all kids should go to college vs. get technical or trade educations. But, because I grew up with parents that did emphasize education, I just struggled to figure out how, if at all, one could reach a kid that comes to school and just shuffles their way from class to class without giving ANY effort, knowing that kid is going home to a place where no one cares what happened to him at school that day.