Coronation Street viewers have started to wonder if Sarah Platt, who has been played by Tina O'Brien since 1999, could be behind the long-running soap's latest murder18:33, 29 May 2026Coronation Street fans think Sarah Platt could be about to be exposed as a killer. The factory supervisor, who has been played by Tina O'Brien on the ITV soap since 1999, is currently amongst those dealing with the aftermath of the death Theo Silverton, who had been abusing her best friend Todd Grimshaw (Gareth Pierce) for almost a year.‌Theo's death all came at the end of a much-hyped Murder Week, in which he and four other antagonists had been lined up as potential victims as part of a flashforward.‌Pretty soon after the dramatic night, bosses of the programme revealed that Todd himself, Theo's colleague Gary Windass (Mikey Norton), Todd's surrogate father George Shuttleworth (Tony Maudsley), his partner Christina Boyd (Amy Robbins) and Theo's ex-wife Danielle Anderson, played by former Emmerdale star Natalie Anderson, were the official suspects.‌Also in the line-up was Todd's adoptive daughter Summer Spellman (Harriet Bibby) and in recent episodes, DS Lisa Swain, who has a long history of locking innocent people up, charged her with murder. But now fans have started to wonder if Sarah is behind the killing, perhaps in what was a desperate bid to protect her friend from further abuse.On the night of the murder, Jodie Ramsey (Olivia Frances Brown), who was introduced as the long-lost sister of Shona Platt (Julia Goulding) and has a mysterious streak about her, trashed number eight and knocked Sarah unconscious when she walked in the house.‌Sarah is currently unaware who attacked her on that night, and has dealt with subsequent pressures in life and at work by hitting the bottom, but viewers have started to speculate that she had already carried out a fatal attack of her own by the time it came about.One fan wrote on Reddit:" Does anyone else think Sarah was the one who murdered Theo? It could have happened before she went into the Platt house, and she's been acting weird since, I know they are saying it's from the attack, but I think it could be more than that."‌Another agreed as they said: "Definitely does feel like there’s more to her current state than just being knocked over the head," and another said: "A lot of people are speculating that there could be an affair going on with Gary and Sarah, so I wouldn’t be surprised if that’s the case!A fourth said: "Omg I hadn’t thought of this, OP, but what if she was assaulted, then in a black out state killed Theo? Has no memory of course, and won’t be convicted because of it? She was so vague when she returned from the “hospital” when asked by Gary."However, others were left unconvinced that Sarah would be about to leave the soap entirely, which is presumably what would happen if she was handed a murder sentence.‌Dismissing the theory that Sarah killed Theo, one fan said: "No because I doubt Sarah would be leaving Corrie. It’s more likely going to be Theo’s son or someone expendable."But another said: "Does the person who did it have to leave the show? I don’t see why they can’t ’get away with it’ in some way especially with the incompetence of the Weatherfield police," and a third joked: "They really are like the cops on Benny Hill..."Actress Tina O'Brien took over the part in 1999 play out a historic teenage pregnancy storyline and remained with the programme until 2008, having been central to numerous kidnap plots and the storyline that saw her mother on-screen Gail (Helen Worth) marry infamous serial killer Richard Hillman.Article continues belowPrior to her 2015 comeback to Coronation Street, Tina appeared in Waterloo Road, Call The Midwife and competed on Strictly Come Dancing but has been a permanent fixture on the programme once again since her return more than a decade ago.Coronation Street airs Monday to Friday at 8:30pm on ITV1 and is available to stream from 7am on ITV X.* Follow Mirror Celebs and TV on TikTok , Snapchat , Instagram ,Twitter ,Facebook , YouTube and Threads .