Abstract:

Objective Flock fibres are proposed as a tracer in cases where secondary transfer of the tracer is needed. Methods The research was carried out following a case in which people were suspected to commit large numbers of burglaries. Fibres were applied to the vehicle of the suspects and collected from later crime scenes. A device was developed to assist in the application of fibres and a number of experiments on secondary transfer were carried out. Results The device can be used to apply many fibres homogeneously in a short time. A single contact will not fully deplete the first surface from flock fibres. 1%~15% of the fibres are transferred to the 3rd surface representing the crime scene. The actual number of transferred fibres is dependent on variables such as the choice of surfaces. Conclusion The results indicate that， given the selected parameters， it is realistic to expect that relatively large numbers of fibres are transferred to a crime scene and can be collected.

Key words: tracer, fibre, secondary transfer, fibre comparison, burglary