A supermarket worker has been found guilty of murdering his wife and teenage daughter after he slit their throats in a jealous rage because he was losing his “controlling” grip on the family. Marcin Zdun killed 40-year-old Aneta and 18-year-old Nikoleta at the family home in Salisbury, Wiltshire, wrongly suspecting they were both having an affair with a supermarket colleague. On Thursday, the judge, Mr Justice Chamberlain, adjourned the case for sentencing at Winchester crown court the following day. When Zdun was arrested at the scene of the killings in June, police found a folding lock knife in his trouser pocket with blood stains on the blade and handle. Jurors heard the 40-year-old believed both his wife and daughter, a student, were having an affair with a man at the Tesco supermarket where he worked. He had become increasingly angry and violent towards his wife, a care worker, because she was not cleaning the house or making meals for the family as he demanded. Zdun would confiscate her car keys and even disconnect the vehicle’s battery so she could not drive it, even to visit her clients. He also fell out with his daughter after she disobeyed him by getting piercings and tattoos, having turned to her mother for permission instead. The prosecution said his family had become terrified of him in the days leading up to the fatal attack and his wife had sent a message to her mother saying: “I don’t want him to kill us, he’s a psycho.” Giving evidence in court, Zdun denied “bullying” his wife but admitted she had asked him to leave the family home after he had attacked her in the kitchen. Zdun moved out but armed himself with the knife and went back to kill his wife and daughter. Horrified neighbours told the court how Zdun repeatedly plunged the blade into the defenceless pair in their garden, with Aneta desperately trying to save Nikoleta by putting her own body in the way of the blows. David Powell said: “There was no humanity in his face whatsoever, just anger – pure anger. I don’t know how you can do that to another human being. His sole purpose was to kill them.” Nicholas Haggan QC, prosecuting, suggested to the jury Zdun felt he had lost “his controlling influence over Aneta and Nikoleta” and this “so angered” him that he decided to kill them. Aneta’s employer, Wessex Care, paid tribute to her as a “beloved colleague and friend”. The company said she was a “well loved and well known” member of staff who worked in the community team.