The police force should have its own psychiatrists in view of the specific pressures officers face, an expert proposed yesterday. The proposal came after schizophrenic officer Yau Chun-sing, 27, was sent to a psychiatric centre indefinitely for shooting dead Chan Kwok-keung, 24, in Aberdeen police station last November. Dr Lee Sing, associate professor at the Chinese University's psychiatric division, said: 'The police are working in a specific environment in which their stress and pressure is different from that of the general public.' He said a stigma was attached to policemen with mental problems. 'The image of the police is tough, as their prime responsibility is to protect the public. But people always regard psychiatric patients as being harmful to society - the other end of the extreme,' he said. He added the service in public hospitals, which was already very stretched, failed to cope with officers' special needs. 'At present, public hospitals can't afford to give special attention to the policeman given the ever-growing waiting lists of mental patients,' he said. A police psychologist concluded Yau was suffering from 'brief reactive psychosis' when he complained he was 'possessed' after witnessing a friend's suicide. A police spokesman said the force needed time to study the proposal.