Medical experts will join the review sparked by Saturday's police killing of a suspect in Aberdeen police station. The investigation will look at the force's psychological services. Constable Yau Chun-sing, the officer who killed Chan Kwok-keung, had been treated for mental problems for two years. Yau, who is being held in Castle Peak Hospital under a special magistrate's warrant, received psychological treatment for two years after watching a fellow officer shoot himself dead at Mongkok police station in 1994. Officials from the Department of Health and the Hospital Authority are expected to help tackle the review's three main target areas. A police spokesman said the review would aim to: Ascertain the adequacy of procedures and services provided to police; Recommend procedures to identify high-risk categories of officers who can be given special attention and professional care and; Ensure adequate provision of specialist care not available within the force with the help of the Department of Health and the Hospital Authority. It will aim to ensure supervisory officers can spot signs of emotional or psychological distress in their men. Review head Chief Superintendent Kevan Cooper said it was too early to expand on specifics, but the review will not study the handling of suspects after arrest. Senior Assistant Commissioner Benny Ng Ching-kwok defended police post-arrest procedures and said it was his belief that video cameras in the interview room would not have stopped the tragedy. 'Our initial review has found nothing that would suggest there was any deviation from established procedures,' he said. 'Procedures are only guidelines to be acted on in given situations by thinking, professional police officers, not robots.' Mr Ng said an independent inquiry was unnecessary. 'This is a criminal investigation; we are professional criminal investigators and perfectly capable of handling it.' The review body will report directly to Police Commissioner Eddie Hui Ki-on. The Police Psychology Service Group was set up 14 years ago and has dealt with about 2,000 mostly minor cases, such as stress.