A FEMALE police officer from Lifton has denied attempting to pervert the course of justice during a police inquiry into sexual assaults on girl cadets at an air training corps group where she was the commanding officer. Sarah Cohen, aged 36, pleaded not guilty to two charges of attempting to pervert the course of justice and two of misconduct in public office when she appeared at Exeter Crown Court. They all relate to a police investigation in November 2011 into allegations of sexual assaults by air training corps sergeant James Reading on teenaged members of Miss Cohen's ATC troop in Devon. James Reading, from Plymouth, was found guilty in June 2012, in his absence, of groping girls while on night exercises and at illegal under-age drinking parties. He received a ten year jail sentence. Miss Cohen has been bailed to appear at a trial which is expected to take three weeks next January at Exeter Crown Court. The charges specify the acts which she is alleged to have carried out on November 20 to 23, 2011. She is accused of tampering with potential evidence by failing to seize a knife and cleaning it and influencing the decision to hold Mr Reading under the Mental Health Act when he was arrested at Meldon Quarry. She is also accused of failing to report his threat to harm himself. The second charge of attempting to pervert the course of justice alleges she failed to pass on an allegation by the parents of a girl cadet to police and speaking to them 'in terms calculated to encourage them not to seek an investigation'. The charge also accuses her of failing in her duty as the commanding officer of an air cadet group to pass on allegations to the police. The two misconduct charges relate to the same events.