Technical Report A light touch; Reviewing the relative effectiveness of light sources and physical/chemical techniques for fingermark retrieval in casework

This study reviewed the efficacy of non-contact light source examinations of serious crime scenes using ultraviolet A (UVA) light, bespoke white light and lasers, compared with subsequent powdering or chemical enhancements. Twenty-six examinations of serious crime scenes or motor vehicles were analysed, from which 655 areas of retrieved fingermark or friction ridge detail¹ where reported on. It was found that undertaking a light source examination revealed equivalent numbers of marks to aluminium powder and chemical enhancements, with only a 4 % duplication rate between optical and physical/chemical techniques suggesting that both approaches are supplementary and should be used sequentially to each other.