A BRUTAL serial rapist is terrorising Tuen Mun public housing estates. Police believe the murder of Mak Siu-han in the early hours of Wednesday morning can be blamed on the same man responsible for attacks on five other women, one of them fatal. Her killer is not the only assailant at large. In the Tuen Mun area alone there have been 16 rapes and 88 cases of indecent assault in the past year. Residents are understandably concerned about the need for greater security. Entrances to buildings are unguarded and have no gates, hallways are poorly lit, while multiple stairwells offer easy hiding places. The police say patrols have been increased since the first murder in February, despite the shortage of manpower. Although it is reassuring to have a stepped-up police presence in the area, it is clearly not enough. Neither the police nor private watchmen could ever hope to provide a perfect security cordon. But guarded entrances, better lighting and above all, permanently monitored closed circuit television in corridors and stairwells, would give residents a greater sense of safety. Better security measures such as secure entry gates, cameras, emergency telephones and watchmen cost money. Public housing tenants will be tempted to look to the Government to foot the bill in helping make the estates safer. Although the Government will be loathe to commit public funds to help alleviate the problem, it should not dismiss the possibility outright. Housing estate residents also need to play a role in contributing to their own security and well-being. A small monthly management or security fee paid by each household towards improving security in the estates should not be considered an unreasonable request. At a time of such heightened concern in protecting the innocent from sexual assault and possible murder, the price may be worth paying.