No doubt heavy drug users. I hope they get the help they need (actually I hope they get their asses kicked in prison... daily)
Or drunks
Drunks beat wives and kids as I recall seeing as a kid before drugs
I would wager a drunk will beat you quicker than a heroin addict and far less than a stoner
Drunks meth and cokeheads
Pretty much the same meanassed selfish behavior