MS Christine Loh's confusion (South China Morning Post, December 19) over the 'new' police caution to suspects in the UK, stems from a fundamental misunderstanding, common even amongst lawyers, about suspects' rights upon arrest. There is no such thing as a 'right to silence'. No-one can be forced, threatened or induced to answer police questions. The so-called 'right to silence' is no more than a prohibition on the drawing of adverse inferences at trial from a refusal to answer questions by the police. This is not merely semantics, for what the 'new' UK caution does is to warn a suspect that under the revised law, a court may draw an adverse inference from his failure to indicate a defence to an allegation if such defence is known to him at the time of his being questioned. The purpose of the new legislation in the UK is to combat 'ambush' defences where the police and prosecution have to investigate and prepare a case for trial without knowing what is the real defence to the charge. This frequently results in a huge waste of resources and court time and occasionally allows the guilty to go free. It is quite unnecessary in a sophisticated society, provided that suspects' rights are adequately protected by other measures. There is nothing new in the idea: defendants in the higher courts in Hong Kong are already required to give advance details of any alibi so that it may be investigated. Ms Loh's apprehension about the introduction of similar legislation in Hong Kong is, however, well-founded. It can be justified in the UK where the provisions of the Police and Criminal Evidence Act (PACE), the mandatory tape recording of all interviews and wide ranging Codes of Practice for police conduct, give a large measure of protection to suspects, including the right to legal representation during questioning. Here, the Security Branch, no doubt under pressure from the police, has consistently refused to countenance the introduction of similar safeguards and insists on maintaining the present primitive system of police procedures. It is said that any changes would impede the investigation of crime by the police and help criminals to escape justice. This is patent nonsense. Similar fears were expressed by British police before PACE. Now they are strongly in favour of PACE with its guidelines for their activities, and its controls allow the introduction of legislation permitting adverse comment at trial on the silence of a suspect, though only in appropriate cases. Honest policemen have nothing to fear from legislation protecting suspects' rights. Anyone with any knowledge of the courts in Hong Kong will know that untold millions of dollars of taxpayers' money are used each year investigating the voluntariness of confessions allegedly made by suspects. Until the introduction of PACE, the same situation applied in the UK. But with proper controls on police activity, most of that time-consuming and expensive business has now gone, there are fewer contested cases and a large sum of public money has been saved. Suspects are substantially protected from police malpractice and the guilty are more effectively brought to justice. These are aims which Hong Kong would be well advised to adopt. Unfortunately, defence lawyers have a vested interest in the present system, which encourages more and lengthier trials; the police too have a vested interest because they fear a loss of power; and the Legal Department is too craven to take the lead. Perhaps it is time for the judiciary to speak out.