RESPONSE — thanks for your response. The way you have written it, I do not know if you are simply adding to the conversation (great!), agreeing (super), or critiquing (also great when done respectfully).
It is true that a lot of serial killers do suffer childhood trauma. That doesn’t mean that trauma comes exclusively from the mother or even the parents.
Abuse doesn’t directly correlate with someone becoming a serial killer. A lot of abused children grow up to not be abusive maniacs, and the statistics we have on serial killers are from the ones who have been caught. For obvious reasons, not every serial killer has been reported.
So it's certainly not an inevitability. There are also serial killers who don’t have such trauma in their pasts.
From a narrative standpoint, the way Penny was depicted made me uncomfortable since she was an abused woman in an abusive relationship. We simply don’t know enough about the relationship dynamics with her former partner to say whether she was culpable.
Our only source came from an 80s Gotham cop, and the social mores of the time would have blinded them from empathizing with her.