In spite of being aware of Paul Paget-Lewis's obsession with Ahmed Osman, whom he taught at a school in Hackney, east London, and his harassment of the boy and his family, detectives did not pursue the teacher after a raid on his home failed to find him, it was claimed.
Three months later, in March 1987, Paget-Lewis, who had changed his name to Osman because of his infatuation, took a shotgun to the Osman family home in Clapton, east London, and killed Ali Osman, the boy's father, and seriously injured Ahmed, then aged 15.
He then went to the home of the school's deputy headmaster, who had warned him about his behaviour, shot and seriously injured him and killed his 17-year-old son. Paget-Lewis was arrested shortly afterwards and sent to Broadmoor.
John Hendry, QC, for Ahmed Osman and his mother, Mulkiye Osman, who are suing the Metropolitan Police for negligence, told the Court that on the part of the police there had been 'a simple failure to do an obvious thing' when they received the warnings. Unlike other cases where the police had been accused of negligence because they failed to prevent a crime, it could not be argued that police were unaware of the identity of the criminal or the potential victim.
Mr Hendry was responding to an appeal by the Metropolitan Police, which claims the case should be struck out because police are covered by public interest immunity and cannot be sued for alleged failures in the detection and supression of crime. The appeal, before Lords Justices McCowan, Beldam and Simon Brown, is against a High Court ruling last December that the action could proceed. The Osmans are also suing Dr Hugh Ferguson, an ILEA psychiatrist, who is not involved in the appeal.
Mr Hendry said that between October and December 1987, Paget-Lewis, who had been dismissed from his job, had been seen by a policeman about acts of vandalism at the Osman home. He told the officer he was in danger of doing 'something criminal insane'. In December he told an ILEA inspector that he would 'do another Hungerford'. That was also passed to police.
Two days later, detectives went to Paget-Lewis's home to arrest him for criminal damage. He was not there. 'Between then and three months later, the police did not arrest Paget-Lewis. It was their failure to arrest that allowed Paget-Lewis to commit the murder,' he said.
Shortly after the arrest attempt, detectives took a statement from a person whose car had been rammed by Paget- Lewis who said that the teacher had said he was not worried 'because he would end up doing life. This ought to have put police on their guard,' Mr Hendry said.
Police knew that Paget-Lewis was enagaged in a campaign of harassment which included 'criminal and violent acts'. They had assured both Mr Osman and the school that they would protect the family.
Simon Freeland, for the Metropolitan Police, argued that the case should be struck out because of the decision of the House of Lords to reject the action brought by the parents of Jaqueline Hill, a victim of Peter Sutcliffe, the Yorkshire Ripper, alleging negligence by West Yorkshire Police because they had failed to catch him. Although police could be sued over the actions of individual officers which caused injury to another person, in no case had the police been found liable for failing to apprehend a criminal who caused injury to a third party. The Hill case gave police immunity from negligence actions arising out of the investigation of crime and the facts were indistinguishable from the Osman case.
Judgement in the appeal will be given today.Reuse content