The Differentiation of Primary and Secondary Bead by Metallography




Bead, Globule, Metallography, Fire investigation, Forensic science


There is a lack in literature about forensic fire investigations due to electrical causes, such as consistent and reproducible techniques for globules and beads presents in wires. Although materials science and metallurgy have available techniques for copper melting analysis, there is not a consensus about which of those methods would be appropriate. Thus, this study aims to discuss characteristics that would make it possible to distinguish between globules and beads through metallographic examination in traces obtained from real fire scenes. Therefore, it was possible to establish which of them had primary or secondary characteristics of fusion trace using metallography. Thus, when corroborated with other elements of the scene this conclusion allows criminal expert to conclude about the circumstances of the fire. Although it is not an innovative technique, the development of the present study is relevant regarding the absence of scientific studies dealing with this topic mainly in Brazil.

Author Biography

André Carrara Cotomácio, Instituto De Criminalística De São Paulo

Engenheiro de Segurança do Trabalho, é Mestre em Engenharia de Produção e Graduado em Engenharia de Controle e Automação. Possui MBA em Finanças e Pós-Graduação em Administração de Empresas. É Pós-Graduando em Auditoria, Gestão e Perícia Ambiental (2019); e em Engenharia Diagnóstica: Patologia, Desempenho e Perícias na Construção Civil (2020). Atua como Perito Criminal no Instituto de Criminalística da Superintendência de Polícia Técnico-Científica do Estado de São Paulo, na área de Engenharia Forense.


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How to Cite

Cotomácio, A. C., & Schröer, G. (2020). The Differentiation of Primary and Secondary Bead by Metallography. Brazilian Journal of Forensic Sciences, Medical Law and Bioethics, 10(1), 14–35.



Original Article