Fair points. But by 17 there are some things, many important, that are simply out of the control of many parents. I get that really involved parents, and honest/insightful parents would see the issues TM was having and perhaps found a way to resolve them.
TM's folks were struggling for their own livelihoods and it was a broken family. I get if they were better parents TM may have not been into Street Fighting, theft, truancy, but it's no guarantee either and I don't expect any parent to be close to perfect in raising a child.
Either way a worthwhile discussion on that front, but it's mostly acceptance of things out of ones control is where I sit at the moment regarding TM's folks responsiblity for TM's choices prior to and leading up the night TM was killed.