So, once again, deal with your landlord.
Tossing out the word "predisposition" carries absolutely no legal significance, and were you to actually look at Massachusetts case law you would find that the term is used infrequently and not in the manner you suggest. Your belief that the word "predisposition" has a magical significance that can turn your gripe against your neighbor into a windfall victory in the lawsuit lottery is not grounded in reality.Quoting tmacj19
Meanwhile, you can read about how Massachusetts courts treat character evidence here.

