A handheld or portable detection system with a high degree of specificity and accuracy, capable of use at small and substantial standoff distances (e.g., greater than 12 inches) is utilized to identify specific substances and mixtures thereof in order to provide information to officials for identification purposes and assists in determinations related to the legality, hazardous nature and/or disposition decision of such substance(s). The system uses a synchronous detector and visible light filter to enhance detection capabilities.