Police will continue to use laser guns because of their undoubted accuracy and reliability, Police say, adding all other prosecutions for speeding remain valid.

In response to the court findings of a recent speeding case, Police said the laser gun operator in the case followed the procedures detailed in the manufacturer's manual in carrying out his duties.

Acceptable distance

A "Fixed Distance Check" of the laser gun was required prior to and at the conclusion of each operation. The manufacturer's manual required this check to be conducted at 60 metres against a fixed object.

Police said laser gun technology expert Dr Tam wing-yim had confirmed that a distance of 50 metres to 60 metres was acceptable.

The 200-metre test raised in the trial refers to the laser gun scope realignment procedure which only the manufacturer conducts during maintenance and repairs.

During trial, the court referred to another traffic formation's internal training manual, which differed in some respects from the manufacturer's manual.

As a result, the prosecution felt it was unsafe to pursue the original offence and agreed to amend the charge. The decision was made in accordance with established prosecution policy guidelines, Police said.

Manual issues

All other traffic formations used the manufacturer's manual in handling speeding cases, Police added.

As the internal training manual differs from the manufacturer's manual, the Force is examining the matter in depth and will seek expert opinion to ensure operators are provided the best advice.