Man walks into strangers' house, starts stabbing occupants with a machete

What kind of person walks into a stranger's home with a machete and starts cutting the residents?

In a town outside NYC the guy below did just that.

Maybe it's just me but it seems as though we're seeing a LOT more attacks like this.  Is there more insanity now?  More race hate?  (that one seems likely.)  Maybe something bizarre like demonic possession?  MS-13?  Beats me.