THE Legal Department's decision to prosecute three Correctional Services Department (CSD) officers for allegedly assaulting inmates during last April's controversial raid on Whitehead detention centre is welcome reassurance that justice is seen to be done. The inquiry into the raid by Justices of the Peace Andrew Li Kwok-nang and Professor David Todd recorded allegations of assault by a number of Vietnamese and left it to the government to decide whether prosecutions were to be launched. But the long delay in bringing charges had begun to fuel suspicions among concern groups that certain sections of the administration and the police were hoping to let the matter drop quietly. Now that Peter Nguyen, the Director of Public Prosecutions, has decided to go ahead with the prosecution, however, the courts must ensure the case will be pursued without prejudice or favour. Whatever the verdict, the decision to bring charges will alleviate some of the uncertainty that has dogged the lives of all concerned since the raid. Not the least of the uncertainty has been the difficulty facing the Security Branch in choosing which Vietnamese to deport. Even after last week's Orderly Repatriation Programme flights, spokesmen have been giving non-committal answers every time they were asked whether any Vietnamese witnesses or alleged victims had been sent back. Now the branch has at last felt free to state unequivocally that those required for the trial of the three Correctional Services officers are still in Hong Kong. It is a pity the DPP's decision had to wait until after last week's deportation exercises. In the six weeks since the police handed over their investigation of the inmates' complaints, Mr Nguyen has had to consider its findings, the statements of all witnesses, the medical and forensic evidence and the police and CSD videotapes of the raid. Thorough deliberation was no doubt important, but either the decision should have been taken earlier, or the deportation exercise should have been delayed until Mr Nguyen was ready to give his answer. It does the reputation of the Security Branch no good when its officers cannot answer criticisms because the crucial announcements have not yet been made by the DPP.