Anna and Mr Bates find themselves behind bars in dramatic Downton Abbey season finale It's the whodunit that has gripped fans for most of this season - and a new clue has been revealed in the quest to discover who murdered Downton Abbey rapist Mr Green. Green's victim Anna Bates and her husband can be seen sitting glumly behind bars in new pictures from Sunday's season finale and both certainly have motive to have killed the evil valet by pushing him under the wheels of a vehicle in London's Piccadilly Circus. The murder storyline which has gripped viewers and it is not outside the realm of possibility that either Anna or her husband were involved. Could they be involved? Mr Bates and his wife Anna are seen sitting in jail in new promotional shots for the season finale of Downton Abbey as viewers get one step closer to discovering who murdered rapist Mr Green Anna's desire for revenge is understandable - and she was in London on the day of the murder. Also Bates has long known that Green raped his wife, despite her initial efforts to conceal his identity. Guilty party? Rape victim Anna's desire for revenge is understandable - and she was in London on the day of the murder Fans of the period drama reacted angrily and with dismay on social media over the rape scene involving Anna. Mrs Bates, played by Joanne Froggart, is confronted by Mr Green during the scene, who attempts to kiss the married maid against her will. But when Mrs Bates wrestles off the guest valet, played by former EastEnders actor Nigel Harman, he punches her in the face, knocking her to the ground. Waiting to hear her fate: Anna appears to take part in a line-up in the season finale As Mrs Bates screams in agony, she is then dragged into a room and pushed over a table by the male character, who was making his first appearance in the hit series. While the episode did not explicitly show any sexual violence, screaming and the sound of further striking could clearly be heard as an exterior shot of the room was shown while the assault was taking place. A hysterical Mrs Bates appeared in a later scene looking extremely distressed with cuts and bruises on her face as she begged a fellow servant for help. Fans of the period drama reacted angrily on the internet over UK network ITV's decision to broadcast the violent scene, calling the plotline 'morally reprehensible.' Motive: Bates has long known that Green raped his wife, despite her initial efforts to conceal his identity The broadcaster was forced to defend the episode after more than 200 complaints, with some accusing writers of using a sexual assault to 'spice up' the show. Show creator Julian Fellowes defended the storyline, telling the BBC:'The whole point of the way we do things on Downton is we don't do them gratuitously. We are interested in exploring the resultant emotions and the effect these things have on people. 'If we'd have wanted a sensational rape we could have stayed down in the kitchen with the camera during the whole thing and wrung it out. Happier times: It is not all doom and gloom in Downton as new promotional pictures appear to show Lady Rose wearing a huge engagement ring 'The point of our handling is not that we're interested in sensationalising but we're interested in exploring the mental damage and the emotional damage.' Froggatt also chimed in, saying she is 'proud' of Downton Abbey for tackling the controversial subject. The star said it was a 'brave' move by programme-makers to feature such a difficult scene in the normally gentile Sunday night series. Harman, who played the rapist, admitted it was 'a shocking storyline' as he appeared on British show This Morning and added it was 'something that when I was sent the script and read it I was amazing by and excited by, if that's the right word.' Complicated: The engagement is not without complications as Atticus had some female company while on his stag-do. He continued to defend the rape sequence saying 'for a show like Downton Abbey it really leaps out as a bold and risky idea.' However, it is not all doom and gloom in Downton as new promotional pictures appear to show Lady Rose wearing a huge engagement ring. But even that is not without complications as her fiance Atticus had some female company while on his stag-do. The final episode of series five of Downton Abbey will be broadcast on Sunday. What's in store for Mary and Edith? Loose ends for the Crawley sisters are set to be tied up in the series finale