A PSYCHIATRIC patient was battered to death with a brick by another inmate on the day he was due to be discharged from a mental hospital, a court heard yesterday. Siu Yun-ping, 52, had been voluntarily treated for schizophrenia and was asleep on a garden bench at Castle Peak Hospital when he was attacked. His killer, Lau Ping-fun, 48, has suffered from schizophrenia for many years. The court heard Lau, who smiled constantly when questioned about the incident, has been plagued by the noise of buzzing insects in his ears since childhood. He also hears voices criticising him and believes he is being pursued by strangers. Lau pleaded guilty to manslaughter. His not guilty plea to murder was accepted on the grounds of diminished responsibility. Mr Justice Saied ordered that he be detained in Siu Lam Psychiatric Centre indefinitely. Prosecutor Harish Delwaney said Siu was asleep on a bench in the garden of an open ward at 9.15 am on October 1 last year. Lau rushed at him with a brick held in both hands, repeatedly bringing it down on Siu's head. The victim, who lay motionless, began to bleed. He was rushed to Tuen Mun Hospital, where he died 17 days later. Siu had suffered a deep cut to the head and a depressed fracture of the skull. The gaping eight-centimetre-long wound on his upper forehead had caused damage to the scalp, skull and brain. Lau had been harbouring a grudge against the other inmate following an incident 11 days before the attack, the High Court heard. He claimed Siu had grabbed him from behind for no reason. The court heard Lau had been in and out of psychiatric hospitals since 1974. He has lost touch with his parents, three sisters and two brothers, who no longer visited him in hospital. Lau has a previous conviction for wounding, another for theft, and five for criminal damage. Mr Justice Saied said doctors reported that Lau suffered from a grave psychiatric illness. The condition is permanent. In a report submitted to the court, Dr William Green said: 'The chances of him improving in an open environment are nil and it is obvious he should be in a secure situation in the future.'