Some people harbor A LOT of anger and resentment toward people they consider "rich". For no particular reason. I knew a guy like this once. He's not a killer, but if he were I could imagine him choosing a victim based just on his anger that that person seemed to be "rich" and "have it all". I don't think that targeting her because he thought she was rich necessarily means he planned to get a ransom (although it is possible that was his original plan until something went wrong).
ETA: In my experience, these type of people are the type who blame all of their problems on other people or on circumstance. i.e.; getting arrested was the stupid cops fault, breaking up was all her fault, I got fired from my job because my boss is a ****, I got a bad grade because my teacher hates me... etc, etc.
ETA: In my experience, these type of people are the type who blame all of their problems on other people or on circumstance. i.e.; getting arrested was the stupid cops fault, breaking up was all her fault, I got fired from my job because my boss is a ****, I got a bad grade because my teacher hates me... etc, etc.