Determination of firing distance using the rhodizonate staining technique

Abstract

The histological staining technique using rhodizonate is also effective for the determination of the firing distance by examining the distribution and intensity of the staining reaction. The differentiation between absolute close-range shots and long-range shots is generally possible without any doubt. The method is not recommended for routine examinations but it is very useful for cases lacking the possibility to investigate smoke and powder deposits in a criminalistic manner, i.e. surgical skin biopsies of hospitalised victims and skin highly altered by the effects of fire, water or by post-mortem decomposition.

The determination of firing distance applying a microscopic quantitative method and confocal laser scanning microscopy for detection of gunshot residue particles

“…Moreover, this method has the potential to provide quantifiable, measurable, and comparable evidence for estimation of the shooting distances in the reconstruction of events in gunshot fatalities [16,24,25]. Our contribution confirmed the previous results obtained in experimental scenarios [14] showing that the amount and the spatial distribution of GSR deposits in the skin surrounding entrance wounds strictly correlate with shooting distance.…”

“…Smoke stain and interspersions of gunpowder are important histological findings that can be visualized quite well in histological sections by their own coloration without special treatment [18]. After the experimental study carried out by Marty et al [14] who demonstrated that differentiating between the different range shots is possible with the assessment of the distribution of sodium rhodizonatepositive primer particles on and in tissue, we compared the different pattern of sodium rhodizonate-positive deposits with the shooting distance, reliably known by macroscopic and histological characteristics of entrance wounds. The histological sections were also analyzed with a confocal laser scanning microscope.…”

“…Histopathological examination is a component of gunshot wound investigation that may be pivotal to thorough and scientific case resolution [14,18,23]. …”

“…Deparaffinized and rehydrated paraffin sections were coated with a solution of sodium rhodizonate (rhodizonic acid and disodium salt at 97%; Sigma-Aldrich, Basel, CH, Switzerland) at 0.3 g in 100 ml of distilled water and tartaric acid (acid L-tartaric 99.5%, Sigma-Aldrich) at 1 g in 100 ml of distilled water with a ratio 5:1 (five drops of rhodizonate solution and one drop of tartaric acid solution); the reaction time was 1 min. The sections were contrasted with hematoxylin for 30 s, washed, dehydrated, and mounted in Eukit [14].…”

Detachment of the periosteum and soot staining of its underside in contact shots to the cerebral cranium

“…The undermining of the periosteum may exceed the area of intense soot soiling by a few centimeters. However, in these peripheral parts the periosteal surface does not show homogenous soot blackening, but dispersed gunshot residues, similar to the scattered deposits which are seen on the surface of the entrance site in close-range shots [12].…”