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Forensic Science, Medicine and Pathology

12-03-2025 | Original Article

Trajectory- the unseen realm in a firing event: a novel and scientific approach in the identification of optimal recovery zones for gunshot residue micro traces

Authors: Sreelakshmi Krishna, Pooja Ahuja

Published in: Forensic Science, Medicine and Pathology

Abstract

Gunshot residue (GSR) particles, generated during firearm discharge, disperse in the surrounding environment according to physical laws governing the motion of particles. This study analyzes GSR distribution from 9 × 19 mm ammunition along the trajectory with a fixed target. GSR particle count follows a bell-shaped distribution, influenced by velocity, temperature, and burn rate. Understanding this pattern aids in modeling GSR dispersion based on muzzle-to-target distance, improving forensic analysis of shooting incidents. The kinematic behavior of GSR particles observed in this study facilitated the identification of the region exhibiting the highest deposition. The peak particle deposition was detected along the projectile trajectory, specifically at 100–130 cm from the muzzle end, in the direction of fire. This facilitated the identification of the distance at which the probability of obtaining maximum GSR particles is possible. This aids forensic investigations, providing insights into the trajectory, and identifying the potential region of maximum GSR deposition. A significant influence of distance on the number of GSR particle deposition was observed in the study. The study highlights the necessity of GSR collection along the trajectory, where retrieval probability is higher than at the muzzle or target. A methodology using the Trasoscan Laboratory Imaging System (TLIS) for GSR detection and counting is proposed. TLIS demonstrates potential as a primary imaging tool, with analytical data represented as particle frequency in the shooting vicinity. SEM analysis reveals significant deviations in GSR size distribution across muzzle, trajectory, and target, enhancing accuracy by identifying GSR-dense areas for more precise forensic conclusions. The largest GSR particles were recovered from the target distance (470–500 cm), suggesting surface modifications upon impact, which can be instrumental in estimating the shooting distance. The proposed approach could be implemented in current analytical pipelines or caseworks.

Graphical abstract

Fojtášek L, Vací́nová J, Kolář P, Kotrlý M. Distribution of GSR particles in the surroundings of shooting pistol. Forensic Sci Int. 2003;132(2):99–105. https://doi.org/10.1016/S0379-0738(03)00018-5.CrossRef

Nunziata C, Rotter G, Nunziata F. Formal relationship between the firearm memory effect and the decay time of the GSR particles present on the Shooter’s hands. Forensic Sci. 2025;5(1):3. https://doi.org/10.3390/forensicsci5010003.CrossRef

Wallace DM. Transfer and persistence of gunshot residue particles [Internet]. West Virginia University Libraries; 2010. Available from: https://doi.org/10.33915/etd.4667

Lindsay E, McVicar MJ, Gerard RV, Randall ED, Pearson J. Passive exposure and persistence of gunshot residue (GSR) on bystanders to a shooting: comparison of shooter and bystander exposure to GSR. Can Soc Forensic Sci J. 2011;44(3):89–96. https://doi.org/10.1080/00085030.2011.10768144.CrossRef

Arndt J, Bell S, Crookshanks L, Lovejoy M, Oleska C, Tulley T, et al. Preliminary evaluation of the persistence of organic gunshot residue. Forensic Sci Int. 2012;222(1–3):137–45. https://doi.org/10.1016/j.forsciint.2012.05.011.CrossRefPubMed

Kara İ, Yalçinkay Ö. Evaluation of persistence of gunshot residue (GSR) using graphite furnace atomic absorption spectrometry (GFAAS) method. Bulg Chem Commun. 2017;49(1):101–8.

Maitre M, Horder M, Kirkbride KP, Gassner A-L, Weyermann C, Roux C, et al. A forensic investigation on the persistence of organic gunshot residues. Forensic Sci Int. 2018;292:1–10. https://doi.org/10.1016/j.forsciint.2018.08.036.CrossRefPubMed

Feeney W, Vander Pyl C, Bell S, Trejos T. Trends in composition, collection, persistence, and analysis of IGSR and OGSR: A review. Forensic Chem. 2020;19:100250. https://doi.org/10.1016/j.forc.2020.100250.CrossRef

Tahirukaj M, Surleva A, Vizureanu P, Olluri B, Sandu AV. Assessment of persistence of gunshot residues produced by firearms from criminal cases in the Republic of Kosovo. Appl Sci. 2022;12(20):10477. https://doi.org/10.3390/app122010477.CrossRef

10.

Jalanti T, Henchoz P, Gallusser A, Bonfanti MS. The persistence of gunshot residue on shooters’ hands. Sci Justice. 1999;39(1):48–52. https://doi.org/10.1016/S1355-0306(99)72014-9.CrossRefPubMed

11.

Tarifa A, Almirall JR. Fast detection and characterization of organic and inorganic gunshot residues on the hands of suspects by CMV-GC–MS and LIBS. Sci Justice. 2015;55(3):168–75. https://doi.org/10.1016/j.scijus.2015.02.003.CrossRefPubMed

12.

Trejos T, Vander Pyl C, Menking-Hoggatt K, Alvarado AL, Arroyo LE. Fast identification of inorganic and organic gunshot residues by LIBS and electrochemical methods. Forensic Chem. 2018;8:146–56. https://doi.org/10.1016/j.forc.2018.02.006.CrossRef

13.

Krishna S, Ahuja P. A chronological study of gunshot residue (GSR) detection techniques: a narrative review. Egypt J Forensic Sci. 2023;13(1):51. https://doi.org/10.1186/s41935-023-00369-8.CrossRef

14.

Bhattacharyya CN. Dispersion of firing discharge residues using a maxwellian model. Forensic Sci Int. 1989;42:271–7.CrossRef

15.

Bhattacharyya C. Dispersion of firing discharge residues using a modified maxwellian model. Forensic Sci Int. 1990;47:31–7.CrossRef

16.

Ramza H, Azizan LH, Kamaruddin NH, Ab-Rahman MS. The critical observation of possibility analysis of particles in the Maxwell-Boltzmann distribution law. 2012.

17.

Hernandez H. Standard Maxwell-Boltzmann distribution: Definition and properties. 2017.

18.

Félix, Zapata. María López-López, José Manuel Amigo, Carmen García-Ruiz, Multi-spectral imaging for the Estimation of shooting distances. Forensic Sci Int. 2018;282. https://doi.org/10.1016/j.forsciint.2017.11.025. Pages 80–85, ISSN 0379–0738.

19.

Stamouli A, Niewöhner L, Larsson M, Colson B, Uhlig S, Fojtasek L, Machado F, Gunaratnam L. Survey of gunshot residue prevalence on the hands of individuals from various population groups in and outside Europe. Forensic Chem. 2021;23:100308. https://doi.org/10.1016/j.forc.2021.100308.CrossRef

20.

Gassner A-L, Weyermann C. Prevalence of organic gunshot residues in Police vehicles. Sci Justice. 2020;60(2):136–44. https://doi.org/10.1016/j.scijus.2019.09.009.CrossRefPubMed

21.

Oscar Black, Samuel Cole Smith, Courtney Roper,Advances and limitations in the determination and assessment of gunshot residue in the environment, Ecotoxicology and Environmental Safety, Volume 208, 2021, 111689, ISSN 0147-6513, https://doi.org/10.1016/j.ecoenv.2020.111689.

22.

Beyond the shot. Exploring secondary transfer of gunshot residue on common surfaces and the impact of hand cleaning methods. Forensic Sci Int, 361, 112135. https://doi.org/10.1016/j.forsciint.2024.112135

23.

Wongpakdee T, Buking S, Ratanawimarnwong N, Saetear P, Uraisin K, Wilairat P, Tiyapongpattana W, Nacapricha D. Simple gunshot residue analyses for estimating firing distance: investigation with four types of fabrics. Forensic Sci Int. 2021;329:111084. https://doi.org/10.1016/j.forsciint.2021.111084.CrossRefPubMed

24.

Merli D, Amadasi A, Mazzarelli D, Cappella A, Castoldi E, Ripa S, Cucca L, Cattaneo C, Profumo A. Comparison of different swabs for sampling inorganic gunshot residue from gunshot wounds: applicability and reliability for the determination of firing distance. J Forensic Sci. 2019;64(2):558–64. https://doi.org/10.1111/1556-4029.13870.CrossRefPubMed

25.

Krishna S, Ahuja P. A Study on the correlation of the physico-chemical properties of Gunshot Residue (GSR) particles with distance using a 9×19 mm Indian ammunition. Forensic Sci Med Pathol. 2024 Dec;20(4):1371-1387. doi: 10.1007/s12024-024-00826-3. Epub 2024 Jun 11. PMID: 38861199.

26.

Trejos T, Arroyo L, Menking-Hoggatt K, Ott C, Vander Pyl C, Feeney W et al. Fast screening of firearm discharge residues by laser-based spectrochemical methods, electrochemical sensors, and chemometrics. 2022.

27.

Gerard RV, McVicar MJ, Lindsay E, Randall ED, Harvey E. The long range deposition of gunshot residue and the mechanism of its transportation. Can Soc Forensic Sci J. 2011;44(3):97–104. https://doi.org/10.1080/00085030.2011.10768145.CrossRef

28.

Brożek-Mucha Z. Distribution and properties of gunshot residue originating from a luger 9 mm ammunition in the vicinity of the shooting gun. Forensic Sci Int. 2009;183(1–3):33–44. https://doi.org/10.1016/j.forsciint.2008.10.010.CrossRefPubMed

29.

Brożek-Mucha Z. Variation of the chemical contents and morphology of gunshot residue in the surroundings of the shooting pistol as a potential contribution to a shooting incidence reconstruction. Forensic Sci Int. 2011;210(1–3):31–41.CrossRefPubMed

30.

Zain ZM, Jaluddin SN, Halim MIA, Subri MSM. The effect of type of firearm and shooting distance on pattern distribution, particle dispersion and amount of gunshot residue. Egypt J Forensic Sci. 2021;11(1):10. https://doi.org/10.1186/s41935-021-00225-7.CrossRef

31.

Lin H, Lin T-W. Mechanical proof of the Maxwell-Boltzmann speed distribution with analytical integration. Int J Stat Probab. 2021;10(3):135. https://doi.org/10.5539/ijsp.v10n3p135.CrossRef

32.

Peckham GD, McNaught IJ. Applications of Maxwell-Boltzmann distribution diagrams. J Chem Educ. 1992;69(7):554. https://doi.org/10.1021/ed069p554.CrossRef

33.

Scott CD, Farhat S, Gicquel A, Hassouni K, Lefebvre M. Determining electron temperature and density in a hydrogen microwave plasma. J Thermophys Heat Transf. 1996;10(3):426–35. https://doi.org/10.2514/3.807.CrossRef

34.

Pun K-M, Gallusser A. Macroscopic observation of the morphological characteristics of the ammunition gunpowder. Forensic Sci Int. 2008;175(2–3):179–85. https://doi.org/10.1016/j.forsciint.2007.06.021.CrossRefPubMed

35.

Kara İ. The relationship between Gunshot-Residue particle size and Boltzmann distribution. Forensic Sci Res. 2022;7(1):47–52. https://doi.org/10.1080/20961790.2020.1713433.CrossRefPubMed

36.

Lilley D. Particle trajectories in 3-D space with an Excel/VBA code. 46th AIAA Aerospace Sciences Meeting and Exhibit; 2008 Jan 7. https://doi.org/10.2514/6.2008-1168

Title: Trajectory- the unseen realm in a firing event: a novel and scientific approach in the identification of optimal recovery zones for gunshot residue micro traces
Authors: Sreelakshmi Krishna
Pooja Ahuja
Publication date: 12-03-2025
Publisher: Springer US
Published in: Forensic Science, Medicine and Pathology
Print ISSN: 1547-769X
Electronic ISSN: 1556-2891
DOI: https://doi.org/10.1007/s12024-025-00980-2

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Trajectory- the unseen realm in a firing event: a novel and scientific approach in the identification of optimal recovery zones for gunshot residue micro traces

Abstract

Graphical abstract

Podcast | Sexual health in older age

Springer Medicine

Abstract

Graphical abstract

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