IMO the 2nd commenter offers a far more reasoned response.
The phrase "bad streak" is interesting. I think it's fair to say that most of us have one. With Bundy there was a sense this darkness dominated too much of his mind to be considered merely a "streak", if only going by the shear number of murders and rapes that he committed in his (relatively short) lifetime. There wasn't much room for light.
But maybe even that's being unfair to Bundy. Perhaps if you could somehow quantify how much of his brain was occupied with these dark impulses, it might still only represent a low percentage of his entire character.
It's foolish to identify someone completely with what they DO, whether it's perceived as good or bad. And we shouldn't do it to ourselves either. I can't take credit for not having a mind like Bundy's. Equally, I'm not prepared to take credit for any good deeds I do.
My sister used to love the Lost Prophets. I say used to, because now their front man has been locked away for child sex crimes, she cannot listen to it in the same way. I told her to just forget about "Ian the child molester" and listen to "Ian the musician"! It's not like the "child molester" part of his mind was making the music.
But humans don't see it like that. If want a humorous but endearing example of a sex offender being treat like a human being, watch Curb Your Enthusiasm Season 5 Episode 7. That show can teach us a lot!
https://www.youtube.com/watch?v=C9O1vzGROg8