An assistant at a shelter for people with mental health problems who raped and sexually attacked a mentally retarded woman he met there was jailed for nine years yesterday. Tsui Wing-cheung's crime was made more serious because he preyed on a victim who had difficulty protecting herself, filmed her during the attacks and did not use a condom, Mr Justice Patrick Li Hon-leung said at the Court of First Instance The court heard that Tsui, 58, treated his 25-year-old victim as a 'sex tool', using her to vent his frustration over an unhappy marriage. He was earlier found guilty by a jury of rape, indecent assault and two counts of unlawful sex with a mentally incapacitated person. His crimes took place in August and September last year. The court heard that Tsui touched the breasts and private parts of the victim, who was assessed to be moderately mentally retarded, while they were watching a film at a cinema. He also coaxed her to a love hotel on the pretext that he would perform a massage on her to ease period pains, then made her perform oral sex on him. Tsui twice raped the woman at the home of his victim's mother, who was away. He did not use a condom on either occasion. He also filmed the victim's private parts during the attacks. Tsui claimed in his defence that he was impotent, due to problems with his prostate gland and high-blood pressure. But the jury rejected this claim and ruled that Tsui knew that the victim was mentally retarded and was reluctant to sleep with him. An impact assessment report found that the victim was so psychologically traumatised that she had wanted to leave the shelter where she had met Tsui, but was unable to because of her mental disability. A psychological report showed that Tsui treated the victim as a 'sex tool' to fulfil his desires. He had no intention of developing a long-term relationship with the woman. Tsui's lawyer argued that his client's relationship with the victim was not purely sexual, as they also had other social interactions. The court heard that after the attacks, the victim wrote to Tsui and gave him a bottle of origami paper stars she made, expressing that she was willing to spend her life with him. A psychologist wrote in the report that Tsui had problems in his marriage but, because of his poor problem-solving abilities, he chose not to tackle the issues directly. He was assessed to be unlikely to reoffend. The court heard that Tsui had previously worked as a volunteer for a scout group. The judge adopted a 10-year jail term as a starting point, and reduced it by one year for Tsui's previous contribution to the community.