POLICE authorities in Hongkong and China have a common interest in combatting serious crime. This is because they have a common problem. Criminals do not respect borders. Those who commit crimes in Hongkong and then slip into China remain capable of committing crimes there, too. And they do. So the increasing co-operation between police on both sides of the border is a positive step in the fight to ensure public safety and respect for property. It is producing good results. As the South China Morning Post reports today, the number of armed robberies in the first five months of this year has fallen by almost 40 per cent, compared to the same period last year. It would be unwise to get excited about one set of figures but this is an encouraging trend. The most important point about recent co-operation between the police forces is that it allows for a rapid response to criminal acts. Red tape which formalised, and thus slowed down, police liaison has been eliminated. Instead of having to go through Guangdong and Beijing Interpol, Hongkong police can now deal directly with their counterparts in southern China's city and provincial forces. The posting of two police liaison officers at China's unofficial embassy, the New China News Agency, can also only help communication. Anything which helps communication and, therefore, the speed with which police can act, will assist in catching offenders and deterring would-be criminals. Police work, however, is only part of the fight against crime. The courts have a critical role to play in ensuring that penalties for those found guilty of serious crimes are stiff enough to deter other criminals and potential criminals. Last week's sentences of prison terms of up to 28 years for men who committed armed robbery will send a powerful message that the consequences of committing crime in Hongkong can be dire. A place as vibrant, prosperous and open as Hongkong will never be free of serious crime. But it can, and should, be minimised and this can be achieved only if the police and the judiciary fight a constant battle against criminals. The latest crime statistics are encouraging, for they suggest the fight is being fought well. May this always be the case.