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Bacterial Profiling of Soil For Forensic Investigations: Consideration of Ex Situ Changes in Questioned and Known Soil Samples

NCJ Number
301861
Journal
Journal of Forensic Sciences Volume: 65 Issue: 2 Dated: 2020 Pages: 471-480
Author(s)
D. R. Foran; A. J. Badgley
Date Published
2020
Length
10 pages
Annotation

Since the transfer of soil collected as evidence may undergo change in its microbial makeup over time, leading to false exclusions, the current research stored “known” soils from diverse habitats under controlled conditions, and evidence soils were aged on mock evidence; limited quantities of soil were also assayed.

Abstract

Soil, being diverse and ubiquitous, can potentially link a suspect or victim to a crime scene. Recently, scientists have examined the microbial composition of soil for determining its origin and differentiating soil samples is well-established. In the current study, bacterial profiles were produced using next-generation sequencing of the 16S rRNA gene. Overall, known soils stored open at room temperature were more similar to evidence soils over time than were known soils stored bagged and/or frozen. Evidence soils, even as little as 1 mg, associated with the correct habitat 99 percent of the time, accentuating the importance of considering ex situ microbial changes in soil for its successful use as forensic evidence. (publisher abstract modified)

Date Published: January 1, 2020