First lessons regarding the data analysis of physicochemical traces at activity level in TTADB

Abstract

If transfer traces inform about the source from which they originate, they also have an informative potential on their generating activity. To help practitioners interpret such traces and assess their evidential value at the activity level, this research aims at producing a structured knowledge base on physicochemical transfer traces here defined as ignitable liquids, cosmetics, explosives, narcotics and paints. Studies focusing on background, persistence, transfer and contamination assessment (e.g. washing machines, laboratory), mimicking operative situations (e.g. cross transfers of paint from crowbars onto door frames from a burglary), and covering different supports (e.g. textiles, plastics, doors) were privileged with a special concern for the Canadian relevancy. This research also helps highlighting gaps of knowledge in the overall literature, hence, new research to launch.

RÉSUMÉ

Si les traces de transfert informent sur la source dont elles proviennent, elles possèdent également un potentiel informatif quant à leur activité génératrice. Pour aider les praticiens à interpréter ces traces et à évaluer leur valeur probante en regard d’hypothèses au niveau de l’activité, cette recherche vise à produire une base de connaissances structurée à propos des traces de transfert physicochimiques ici définies comme celles provenant de liquides inflammables, de cosmétiques, d’explosifs, de stupéfiants et de peintures. Des études portant sur le bruit de fond, la persistance, le transfert et la contamination (ex. machines à laver, laboratoire d’analyse), imitant des situations opérationnelles (ex. transferts croisés de peinture de pieds de biche aux cadres de porte lors d'un cambriolage) et couvrant différents supports (ex. textiles, plastiques, portes) ont été privilégiées, avec une attention spéciale quant à leur pertinence pour le Canada. Cette recherche contribue à mettre en évidence les lacunes dans les connaissances de la littérature générale, permettant dès lors de proposer de nouvelles recherches pertinentes à effectuer.

Keywords:

• Ignitable liquids
• cosmetic
• narcotic
• paint
• explosive
• interpretation

Mots-Clés:

• Liquides inflammables
• Cosmétique
• Narcotique
• Peinture
• Explosif
• Interprétation

Acknowledgments

The authors would sincerely like to thank Gabrielle Harvey, now a master student in forensic Chemistry at UQTR for her involvement in the narcotic transfer traces analysis and Jennifer Huynh, now working at the Laboratoire des sciences judiciaires et de médecine légale at Montréal, for her work on the ignitable liquids transfer traces analysis.

Disclosure statement

No potential conflict of interest is reported by the authors.

Notes

1 The term narcotics is used throughout this article and includes psychoactive substances.

2 The ScienceDirect^TM platform offers, following consultation of an article, a series of similar or cited articles that could be of interest for the reader.

3 All data analyzed in this article can be found in the .csv spreadsheet (under .xls format) joined as additional material in TCSF-2020-0045 “The occurrence and genesis of transfer traces in forensic science: a structured knowledge database” accepted by Editor (RL); awaiting DOI.

Additional information

Funding

This work is supported by the Social Sciences and Humanities Research Council (SSHRC) under Grant numbers 430-2016-00051 and 430-2018-00641, from June 1st, 2016 to May 31st, 2022.