DNA typing of cellular material on perforating bullets

Abstract

DNA typing of cellular debris from perforating bullets was investigated following shooting experiments. A total of 14 perforating gunshots were fired into 9 calves. PCR typing of tissue fragments was done using bovine-specific primers flanking a 247 bp segment within the bovine lactoglobulin gene. Positive amplification results were obtained for all 9 hollow point (HP) and all 5 full metal jacket (FMJ) bullets. In contrast to HP bullets the smooth surfaces of the FMJ bullets did not have visible biological material, which resulted in weaker bands in the DNA analysis compared to HP bullets. Tissue seemed to accumulate at the base of the projectiles. Due to the lack of a suitable marker in bovines, only a species identification was carried out on the DNA from tissue on the bullets. The small amount of DNA extract (up to 5%) required for specification is promising for the successful application of a set of short tandem repeat (STR) systems for individualization in humans. By individualizing tissue on perforating bullets, the bullet and the victim it passed through can be linked. This can assist the investigation of gunshot deaths, especially when several persons are involved in a gun fight.

Gunshot-related transport of micro-organisms from the skin of the entrance region into the bullet path

“…The findings described in the present paper once more demonstrate the importance of an interdisciplinary approach to forensic wound ballistics, as was also recently shown by other medico-legal authors [19][20][21][22][23][24][25][26][27][28].…”

STR analysis on perforating FMJ bullets and a new VWA variant allele

“…This again corroborates the assumption that cells are likely to collect at the base of FMJ bullets for aerodynamic reasons (Karger et al 1996). So for recovery of DNA, the whole bullet and especially the base should be swabbed thoroughly.…”

“…In an experimental approach (Karger et al 1996) it was found that far less DNA was recovered from the smooth surfaces of FMJ bullets compared to hollow point bullets. The two FMJ bullets investigated in this report also showed only one minute particle (bullet II) or no attaching material (bullet I) under the macroscope.…”

“…5 moistened fibreglass applicators (3 × 5 mm; Pharmacia, Sweden). The detailed procedure of removing cellular material from bullets is given elsewhere (Karger et al 1996). DNA was extracted using Chelex 100 and Proteinase K (Wiegand et al 1993) and quantified by the slot blot technique as previously described (Waye et al 1989).…”

“…This is especially important if more than one person is injured or several gunshots have been fired. In a previous publication (Karger et al 1996), experimental DNA typing of biological material on perforating bullets was performed using calves. Due to the lack of suitable polymorphic markers in bovines, only a species identification was carried out, but it was suggested that the application of a set of short tandem repeat (STR) systems would also be successful in cases of human individualisation.…”