Who do you think killed Archie Mitchell?

Does anyone think it could have been either A. Jean (Stacey's mum) she has a history of mental illness and she could have overheard the conversation Bradley and Stacey had about Archie raping Stacey or B. (Not sure of his name) but that doctor man that's dating Roxy now, he seems to be in a lot of the episodes all of a sudden and he seems very in love with Roxy, maybe he killed him and that's why Jack is acting all suspicious because he's trying to help cover it up because it's Roxy's boyfriend. Personally I think Jean.