IMO,I think he would have killed with or without Karla.His entire MO was different whenever he was just ''The Scarborough Rapist",and he was still living with his parents at the time.Whereas,when he and Karla were living together,they would go and abduct young girls and bring them back to their home to rape,torture and eventually murder them.His rapes were getting increasingly violent as time went on,and it was feared that he would kill sooner or later.

Don't misunderstand me here,I don't think Karla is any less of a psychopath.You could argue that she's worse for setting up her sister to be raped by Bernardo, (she even participated in her sister's rape) and ultimately cause her to choke on her own vomit. (She even pretended to be her sister,and dressed up in her clothing for Bernardo's pleasure.)

Having read all three books on this case,going by the transcripts of the videotapes Paul and Karla made,I would say Paul was definitely the more ''sadistic'' one,out of the two.However Karla definitely seemed to be a very willing participant,and seemed to be getting pleasure out it all,and didn't even once try to stop any of it.I remember reading that she was alone with Kristen for some time,and refused to let her go.I think there's also a possibility she may have suggested to him that they have to get ''rid'' of the girls,because her parents were coming over for Easter dinner. (she even admits this in ''The Fifth Estate")

I think Karla could be very dangerous if she were to hook up with someone like Bernardo again.But I don't think she wants to damage her reputation (at least in her narcissistic mind.) any further.I think she could have possibly lived a normal life without Paul,but she'd still be a high functioning psychopath in my opinion. (and still is,to this day)\

This is all my opinion based on the whole case,so don't think i'm a psychologist or anything,lol.

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