PCSO Alan Newman said he had received recent reports from across the area such as central heating engineers turning up unexpectedly. He added that other potential con-artists included meter readers and door-to-door charity collectors who had not seemed legitimate. He advised people to have a security device fitted to their doors, such as a chain, and to check ID cards. PCSO Newman also suggested calling a head office number to verify who callers are, if necessary. It is obviously very difficult to investigate these incidents unless police are available immediately to stop-check these persons, he said. And it is difficult to determine historically whether these incidents are attempted scams or genuine traders who have misguidedly made their potential customers suspicious by their actions. INFORMATION: For more details on crime prevention measures, visit www.cambs.police.uk.