A serial sex slasher who preyed on uniformed schoolgirls was jailed for 20 years yesterday. Cheung Pak-hung terrorised girls and women, aged 14 to 27, in 10 attacks. Two victims, aged 14 and 19, were raped. The 14-year-old was attacked in her home after Cheung asked to use her telephone. Sentencing Cheung, 21, Court of First Instance judge Mr Justice Wally Yeung Chun-kuen told him: 'Your crazed and ruthless behaviour led all these victims to suffer emotionally.' The judge said were it not for Cheung's youth, he would have considered sending him away for life. Women's groups applauded the sentence, saying it sent a powerful message to the community. Federation of Women's Centres social worker Lam Yun Kuen said: 'At least somebody recognises the seriousness of men doing such things to women. 'It shows the courts recognise the need to protect women from men who pose a threat to them.' The Association Concerning Sexual Violence Against Women said the sentence showed an encouraging departure from traditional attitudes towards sex crimes. 'These are serious crimes, and yet they have not been given proper attention for a long time,' a spokesman said. At an earlier hearing, computer operator Cheung admitted two charges of rape, six charges of wounding with intent, four robberies and one attempted robbery between August 1995 and January last year. He blamed his desire to slash schoolgirls on an unhappy childhood and vivid sex fantasies. The court heard how he suffered from paraphilia - abnormal sexual behaviour - which sparked an abnormal impulse to molest women. He was particularly drawn to girls in school uniform. Detectives said many of Cheung's attacks only came to light when he confessed. Police did not warn the public a serial slasher was on the loose because they were unaware the attacks were the work of the same man. A spokesman said similar cases in different areas were compared and centralised only if investigators had proof they were linked.