It seems to me that Western Civilization has always distinguished premeditated murder form spur of the moment murder.  I think this is a good instinct.  A forgiving person let’s things go.  He forgives 70×7 times.  He treats every meeting with his brothers as if it were the first.  He doesn’t dwell on those wrongs, rolling them over and over in his mind.  The old fashioned term is stewing.  He gives the person a fresh start at every crossing.

In contrast a crime of passion is momentary anger flaring.  While we should strive to control our temper, this is quite a different thing.  It’s almost a form of accident. Rather than conniving and formulating small nothings into a great evil, it springs upon you suddenly.  It seems that it generally requires larger provocations.  While I’m sure there are crimes of passion involving little more than a printer which ran out of toner, generally what comes to mind is coming home early from work to find your wife in bed with the pool boy.  In that situation it’s only normal that you throw him out the window.  Whether or not he hits the pool or not, is a matter of chance.