An improved method for firing distance estimation on clothing is described. The novel part of the method includes transfer of total nitrite (nitrite ions and smokeless powder residues) from the target to an adhesive lifter. After the transfer, lead and copper deposits around the bullet entrance hole are visualized by rhodizonate and rubeanic acid, respectively. The Modified Greiss Test is carried out after alkaline hydrolysis of the smokeless powder residues on the adhesive lifter.

Experiments were carried out to sample GSR particles (GSRs) from hair using double-side adhesive coated aluminum stubs (the tape-lift method). Although it was claimed in the literature that double-side adhesive tape is not suitable for sampling GSRs from hair, we have not encountered problems with this method. In laboratory experiments it was possible to find GSRs even 24 h after shooting if the hair had not been washed. No significant difference in collection efficiency was found between this technique and the more complicated method of swabbing the hair using a comb with a solvent-damped cloth (the swabbing-and-comb method). It was found that 200 to 300 dabbings are necessary to achieve maximum collection efficiency from hair with the double-side adhesive. As assessed subjectively, it was noted that stickiness is lost after about 100 dabbings. This method has been used in casework in Israel for about a year and a half and, in some cases, GSRs were found in samples from hair but not in samples from hands. We have also studied collection efficiency from hands of the double-side adhesive. It was found that 50 to 100 dabbings are necessary to achieve maximum collection efficiency, while stickiness appeared lost after about 20 to 30 dabbings. No substantial danger of skin debris concealing GSRs was observed.

Examples of some exceptional compositions of gunshot residue particles, formed by using different types of ammunition in the same firearm, are presented. The composition that may be encountered in casework may differ appreciably from the “classic” criteria for identification of gunshot residues. This fact must therefore be taken into account by the expert when interpreting case results, and thus, every case has to be dealt with on an individual basis.

Experiments were conducted to assess the effect of machine washing or brushing of clothing items on Gunshot Residue (GSR) patterns (gunpowder residues, lead, and copper deposits) around bullet entrance holes. Results show that those treatments decrease considerably the amount and density of GSR. However, for close shooting distances not all of the GSR deposits are removed. Remaining patterns may be visualized by specific color reactions and used for shooting distance estimation.

Casework experience in the detection of GSR particles on samples from hands, hair and clothing is reported for the period of 6 years (1989–1994). The overall “success” rate on the examined samples is about 10%. Aspects of the sampling procedures, the number of particles detected per sample and problems of possible contamination are discussed.