The family of a woman murdered by her husband, who is due to walk free later this year, has called on Dominic Raab to review his release. Robert Brown, a British Airways captain, bludgeoned his wife, Joanna, 46, to death with a claw hammer at their family home in Ascot, Berkshire, in October 2010. The couple’s two young children cowered in a playroom as Brown, who believed he was “stitched up” by a prenuptial agreement, killed their mother. He dumped his wife’s body in a makeshift coffin in Windsor Great Park. Brown was acquitted of murder by a jury at Reading crown court in May 2011 but had previously admitted manslaughter on the grounds of diminished responsibility. He was sentenced to 24 years for manslaughter and a further two years for an offence of obstructing a coroner in the execution of his duty, with his release due to take place in November this year. Joanna’s mother, Diana Parkes, 83, has raised concerns about Brown’s release from prison and is calling on the justice secretary to intervene. “Our family is very fearful. Not only our family, but my daughter’s friends and indeed the public at large. I fear for women that he might come into contact with,” she told the PA news agency. Parkes, who hopes to appeal directly to Raab, added: “I would ask him to check our case very carefully and see how absolutely nonsensical it is that Brown is being released halfway through his sentence when the probation service is so understaffed. “And I ask, who is going to monitor him for 13 years of his licence? I really have no faith in the probation service being able to do this.” Brown had driven to his estranged wife’s home to drop off their children after the half-term break. With the youngsters out of sight, he hit her at least 14 times over the head with the hammer. He then wrapped his wife’s body in plastic sheeting, placed a bin liner over her head to “avoid leaving bloodstains”, and dumped her in the car. He took the children back to his home and drove his wife’s body to a prepared makeshift coffin on the Queen’s estate at Windsor Great Park. “I just lost it. I just burst and that’s it,” Brown told the court at the time. “I just blew and the next thing I remember I was standing over Jo and there was blood all over the place.” Brown’s daughter later told police that she had heard her parents “hitting each other”. The Joanna Simpson Foundation has asked people to send a letter to their MP, asking for Brown’s release to be prevented. The charity is also planning an event in Westminster this week to launch its campaign and urge the justice secretary to use his powers to help stop Brown’s release. Speakers at the event are expected to include Joanna’s mother, Diana Parkes, the former justice secretary Robert Buckland, the former home secretary Priti Patel, Carrie Johnson and Joanna’s friend Hetti Barkworth-Nanton. A Ministry of Justice spokesperson said: “This was an appalling crime and our thoughts remain with Joanna Simpson’s family and friends. “The deputy prime minister will do everything in his power to keep the most dangerous offenders behind bars and has pledged to give this case his closest personal attention.”