Ha. Yes. I was just going to write this (in reply to jacquesm's comment above, and also in reply to his parent commenter):

"No, it's that Upton Sinclair quote about salary that is the reason", but you beat me to it :)

When will people learn? Always look for the motive.

As they used to say (and maybe still do) in detective novels, "cherchez la femme", which is French for "search for the woman", i.e. the reason why the crime (of passion) was committed.