Sad truth is, all the antipsychotic drugs in the world won't stop some of these people from doing horrible, crazy things. Back in the day, there used to be asylums, funded by the government, where these people could be institutionalized, for the safety of all, for the rest of their lives if need be. Then, I guess in the 70s and beyond, your government decided they weren't going to fund these institutions any longer, and encouraged medicating those deemed mentally insane, and placing them into society, living in efficiency apartments and the such, with a monthly government check...
and so the story goes....of multiple, horrendous killing sprees, done by people that should be institutionalized, but the government refuses to finance the institutions needed for them.