Elliot Rodger couldn't get a girlfriend and it drove him completely crazy so you can see what many years of lack of sex and intimacy and constant rejection from women can do to a male's mind, changing him from a completely innocent and good person into a remorseless killer.
Whoever Elliot Rodger is or was, he is/was a very sick, mentally ill person. Being horny and lonely does not turn healthy people into a "remorseless killer". Ugh. You really should re-think the cause for Elliot Rodger's despicable behavior. He never was a "completely innocent and good person".