I thought that they sorted out when Michael returned a couple of years ago. Eric confessed that he wanted Elisabeth out of the way and intended to kill her but the Plane crash saved him the bother.

Debbie Dingle was complicit in the murder of her cousin Gennie; she ran her off the road and stood by while her boyfriend, Cameron, finished the job. The police knew this but she didn't even get a caution and nobody in the village ostracised her, not even Gennie's mother. That was very odd writing.

Despite being present at the deaths of three different people Janine has technically never murdered anyone. Barry's death was an accident she pushed him away from her and he fell which is manslaughter at the very most. Same goes for Danielle's death that was a tragic accident she was stood in the middle of the road. And Michael's death was self-defense he was trying to murder her and she killed him to save her own life, her killing of Michael was entirely lawful her only crime there was lying about it and framing Alice. So technically speaking Janine is not a serial killer nor even a murderer.