A former Tory councillor has been convicted of killing his wife by deliberately running over her in his Mercedes at their home in France. David Turtle, 67, was found guilty of murder by a French court and sentenced to 14 years in jail. The court at Agen in south-west France decided Turtle had deliberately driven his estate car at his wife, Stephanie, after an argument over a television programme. Police found the victim under the Mercedes in March 2017; her chest had been crushed and she had suffered severe internal injuries leading to suffocation, according to an autopsy. Turtle had claimed it was a terrible accident and he had no idea his wife, 50, was in front of or under the car when he drove off. Defence lawyers said the accused loved his wife, had no motive for killing her and there was no proof he had done so. Turtle was taken from the court to jail, but has announced he will appeal against the verdict. However, Maître Matthieu Chirez, representing the victim’s sister Catherine Seymour, told the court: “It’s not possible that he is unable to explain what happened. To say Stephanie Turtle voluntarily lay under the wheels [of the vehicle], knowing that he wanted to drive off, doesn’t make sense.” Chirez said Turtle had changed his version of events in the time since the accident. Experts said Turtle would have had great difficulty running over his wife without enormous acceleration of the car. “And that’s what he did, he ran her over … For those few seconds, that’s the horror he did to her,” Chirez told the court. The public prosecutor Patrick Serra said: “David Turtle could not have been unaware that Stephanie Turtle was in front of the car when he drove over her body.” He said there was no evidence the body had been dragged along by the vehicle. He said the accused had begun to change his story as soon as he had access to the investigation file. “He says: ‘I am the only one who knows what happened’, but this doesn’t mean that he is telling the truth … when he pressed the [accelerator] pedal, he crushed her and he couldn’t ignore the fact that she was in front,” Serra added. Maître Laurent Bruneau, from Turtle’s defence team, argued that while Turtle had killed he wife, he had not done so deliberately and said the case had been built on assuming the accused’s guilt. He said that his client was being tried because of inconsistencies in his version of events and asked: “Can anyone be coherent in such situations, after the death of his wife?” “In losing her he lost everything. Of course he killed her, how can it be said otherwise? But it was an accident. He did not see her, and has always said that.” Major Alain Chauvin, a former police officer who investigated the death, told the court that none of the witnesses questioned in connection with the death believed it was an accident. He said Turtle’s wife could not have got in front of the car without him seeing her. In a blog she kept, Stephanie Turtle mused on whether her husband treasured his new car more than he did her, saying he “mollycoddled” the vehicle and lavished it with near-obsessive attention. Jayne Clarke, 63, a friend who lived nearby, suggested David Turtle, who had not learned French, was unhappy in his new home. “I felt David was anxious, he didn’t want to stay in France any more. I felt that David was withdrawing from the [bed-and-breakfast] project and that his enthusiasm seemed to have diminished,” Carmen said. Catherine Goupil, a clinical psychologist, told the court that Turtle had received 140 letters of support from friends who couldn’t understand how he could be accused of murder. She said the couple had “a rather fusional relationship”. The couple had met in Turkey on a holiday for single people in 1996 and had no children. He had left his job as a Mercedes dealer and resigned as a Conservative councillor in Bournemouth’s Kinson North ward, and Stephanie left the human resources department of Dorset council in 2016, to move to Prayssac to run a bed-and-breakfast. “I loved my wife and I love her even more now than before because my heart is broken after what happened,” he said. “Stephanie was the love of my life. It took me 40 years to find her,” Turtle told the court. After the three-day hearing, Chirez told the Guardian: “David Turtle’s version of events made no sense. It’s perfectly impossible that he didn’t see her or hear her that evening, and so it is clear that he deliberately ran her over and killed her. “The technical investigations confirm this fact, and this is what the jury decided. Stephanie’s family and especially her sister are relieved and will continue to show the same decency they have since this terrible crime happened. She was extremely close to her sister and it is obviously a huge loss for her.” He said he and his colleagues would continue to assist the victim’s family.