* * * * * * * * * *
It doesn't make sense that a person should be imprisoned or executed for murdering someone, which causes some x amount of unhappiness, but not for living entire lives of making people painfully miserable in hundreds of small but hostile ways, thousands of times.
The key word here is "cumulative".
The guy with the Sunday morning lawn mower or the owner of the 24/7 barking dog will cause, cumulatively, much more unhappiness in the world than some lowlife who shoots some other lowlife.
Does that mean that having full-time barking dogs deserves the death sentence? Oh yes it does, and I'll be happy to be the one who pulls the switch.
There are those people who are too lazy to lock their own car doors, and carry remote controls for the purpose (is this integrated into people's phones yet?).
In the church parking lot, early Sunday morning, you'll hear a fusillade of honks from all the cars whose owners are not only too lazy, but too thoughtless to turn off the horn alert on their electric locks. I'll bet the people whose bedrooms adjoin the parking lot really enjoy that.