They really didn't build up what Rita knew to the point where she'd think he was a killer. She'd be more likely to think he was a rage-o-holic who'd just hidden it well till then; was having troubles at work that was driving him round the bend; or had relapsed and was using drugs again.
There would have to be a bunch of stuff she found out "off screen" but that would be a cheat. Nope, the writers were right to kill her.
Also things could have taken a twisted turn after such a cliffhanger if it turns out Rita may be growing her own Dark Passenger.
Dark Passengers should be the product of some unusual trauma. As an abused wife, Rita doesn't qualify. If abused wives all became serial killers, the world would be a very dangerous place. Serial killers are rare so the thing that creates them must also be rare. They already show serial killers being unrealistically common (Miami must be the serial killer capitol of the world) which is why I object to the idea of regular characters being turned into serial killers.
It's already ludicrously far-fetched that in one family, the sister was engaged to and nearly killed by a serial killer and then her boyfriend was attacked by a serial killer and then another boyfriend was murdered because he was hunting a serial kiler, and the brother was threatened by a serial killer/co-worker and then his wife was murdered by a serial killer. The Morgan kids are serial killer magnets!
Nah Rita needed to die, but I wish someone would have figured Dexter out.
It's gotta be Deb, but here's a thought: could it be Astor?
In S5, assuming Astor and Cody go back to live with Dex (did he ever legally adopt them?), I can see Astor doing what eldest kids often do in that situation, putting childhood on hold and trying to raise her younger siblings as a parent. Instead of a snotty brat, Astor might become sadly mature and serious, and intensely loyal to Dexter as the head of their fractured household and the guy who has to hold them all together. If she learned some of the truth about Dexter, she'd be too worried about the police breaking up what's left of her family to even think about ratting him out, and a 12 year old kid isn't going to be thinking about abstractions like law and justice.
The reason why I started this thread is because I saw the potential for her having her own dark side with how she “liked” Dexter punching Elliot,
That's just her egotism - she likes having guys fight over her. Common female reaction.
her mysterious past with her first husband, her mention of being quite the party girl back then,
She slept around and was irresponsible. Nothing particularly psycho about that.
saying she accepts Dexter's darkness which kind of hints at her knowing Dexter's secret already,
Or she knows he has a bad temper. Lots of people do. The fact that he seems to be trying to suppress it makes her more understanding.
and covering up for Dexter after she found Paul’s shoe and refusing to tell anyone about it except Dexter.
The writers just plumb forgot about that one.
