Murderers are a rare thing, period.
It’s why murder is newsworthy… if it were common, it wouldn’t be news.
Violent crime of any kind has been in a steady decline - per capita - for decades, now… ask any cop.
There’s a handful of reasons, but in my opinion, the biggest one is that around 1980, we stopped raising kids who were constantly breathing in the fumes from leaded gasoline.
Seriously.