POLICE believe a serial rapist, who is preying on girls as young as eight years old, is targeting Tin Shui Wai new town in the New Territories. They have made it a priority to track the man who has raped two young girls and attacked three others since May this year. Police are making arrangements with parents to ensure that children in the area do not have to walk home from school alone. With the help of a computer they have drawn up a profile of the man, who is believed to be in his 30s or 40s. Senior staff officer (crime), Detective Senior Superintendent Martin Cowley, said: ''There is no need for the residents to panic but certain common sense precautions should be taken.'' Mr Cowley admitted he would feel uneasy letting his own children out alone in Tin Shui Wai and urged parents to make sure their children were always accompanied. He said the behaviour of the rapist was ''beyond the comprehension of a normal man''. Police believe he attacked his first victim on May 2 when an eight-year-old girl was assaulted on the first floor of Yiu Shing House, in Tin Yiu Estate. Just over a week later, on May 10, he is believed to have struck again with the attempted rape of a nine-year-old girl on the second floor of Shui Choi House, Tin Shui Estate. On May 22, a 12-year-old girl was raped in an empty flat on the 36th floor of Yiu Shing House, Tin Yiu Estate. Police believe the rapist then laid low for three months before attacking and raping a 12-year-old girl on August 25 on the first floor of Shui Kwok House, Tin Shui Estate. Tin Shui Wai divisional commander, Chief Inspector Stephen Ho Wai-ming, described how a 10-year-old girl had escaped from another sexual attack last Sunday. ''She was dragged to the staircase landing between the 36th and 37th floors of Yiu Fung House, Tin Yiu Estate. She resisted the sexual assault and chased him until she became frightened and screamed on the 29th floor,'' he said. The case was handed to detectives looking into other rape cases in the area because the girl's description of the man was similar to that of the serial rapist. ''It seems to be the same person, as the girl had told us the man had a mole on his cheek and was about 30 to 40 years old. The suspect has a dark complexion and is about 1.70 to 1.72 metres tall,'' Inspector Ho said. A man was held for questioning after the attack but was later released. Inspector Ho said police were studying ways to strengthen community awareness among families and schools. ''Apart from school talks we hope to have discussions with volunteers, interest groups and the Housing Department to see if it is possible to have designated pick-up points to enhance personal security,'' he said. The idea was for volunteers to escort children home if their parents were working. Inspector Ho believed the rapist had taken advantage of people moving into the new town and that many units were empty because they were under decoration. ''We think the culprit is quite familiar with housing estates here in Tin Shui Wai,'' he said, adding that most of the victims were assaulted inside vacant flats. The head of Hong Kong University's department of psychiatry, Professor Felice Lieh-mak, believed the serial rapist was a paedophile. ''He finds young children sexually desirable because they are young, vulnerable and defenceless. ''Another type of person is a latent homosexual who doesn't go to boys, but young girls who look like boys because their sexual organs have not developed. ''He tends to look for girls who have not reached sexual maturity.'' She said such people were similar to other sexual deviants such as peeping Toms and exhibitionists. Professor Lieh-mak said the problem could be attributed to child pornography. ''Such a market has been generated in New York, Los Angeles, San Francisco and Amsterdam,'' she said, believing that some of these films and videos might have been made in Hong Kong. Professor Lieh-mak said while people were reluctant to talk about child sexual abuse, it did not mean it did not happen here. Hong Kong University has a sex clinic to treat sexual disorder and deviations using psychological and behavioural approaches.