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Making Use of What's Not Visible in Trace Evidence Examinations

NCJ Number
Date Published
July 2020
3 pages

This article describes how, with few exceptions, nanoparticles and sub-visible particles are routinely overlooked by forensic investigators and presents a practical framework that enables the identification and significance of trace evidence particles.


Engineered nanoparticles have become ubiquitous in modern society, in everything from sunscreen to beauty products to clothing. NIJ-funded scientists noted that except for gunshot residue analysis, nanoparticles and subvisible particles are routinely overlooked by forensic investigators. This article describes how those researchers developed a framework that would enable forensic laboratories to use existing equipment to identify and interpret the significance of smaller particles in a practical manner. The scientists stated that there "is virtually no published information on the population of subvisible particles present in real-world forensic samples, nor is there data on the prevalence, transfer, and persistence of nanoparticles within a given substrate or environment."

Date Published: July 1, 2020