That was tragic. The guy was struggling with a mental crisis and was armed and unless those cops had bodycams there will never be any trust in their story. Bottom line is that a knife is most definitely a deadly weapon and if I'm armed and an unstable person comes at me with a blade, I'm putting him/her down. I wonder if extreme situations like this would justify the risk of using a fast-acting tranquilizer on a violent or manic individual. The person could have a drug interaction or allergy and die as well but it seems like it might be worth it in some cases.