A DISTURBED teenager convicted in the High Court of attempting to rape a 16-year-old girl was committed yesterday to Siu Lam Psychiatric Centre for three years. Mr Justice Leong said the offence committed by Chan Koon-chiu, 18, would normally require a jail sentence of four to five years. However, he accepted it was not premeditated, and that jail would be unsuitable given Chan's psychological problems. Chan had denied the charge. Two other men faced trial with Chan. The jury was unable to reach a verdict on a charge of rape laid against Kwok Wing-hing, 20, and acquitted Chow Ka-wah, 16, of indecent assault. Kwok will be retried at a later date. The court accepted that Chan suffers from schizophrenia arising principally from his abuse of drugs. Before his trial, a jury was empanelled to consider whether Chan was fit to plea. It decided he was not sufficiently disabled to be unfit for trial. During the trial, prosecutor David MacKenzie-Ross said the attempted rape arose from a telephone introduction game. On July 5, 1992, the game linked up the victim with Kwok and after chatting for some time, the two arranged to meet later that day. Kwok took her to a flat in Sheung Shui where Chan, Chow and two or three other men were present. They chatted and played the telephone introduction game. Some time after midnight, Chan attempted to rape the girl, but failed. Counsel for Chan, Robert Andrews, said in mitigation his client was an extremely ill young man who had been suffering from schizophrenia for a year before the offence. But since Chan began to receive treatment, there had been a marked improvement, Mr Andrews said.