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Presumptive Field Testing Using Portable Raman Spectroscopy

NCJ Number
Stephana Fedchak
Date Published
January 2014
100 pages
Recognizing the inconsistency and subjectivity involved in its current use of color test kits to presumptively identify cocaine, methamphetamine, and marijuana in the field, the Forensic Laboratory of the Las Vegas Metropolitan Police Department (LVMPD) researched and improved existing Raman field technology for use in the presumptive analysis of controlled substances in the field.
By testing handheld devices in the lab and in the field using a Raman microscope, the LVMPD Forensic Laboratory determined that portable Raman technology is an effective and reliable tool for presumptively identifying methamphetamine and cocaine in the field. The laboratory has also identified the characteristics of portable Raman technology that need further improvement in order to expand the number of drugs that can be presumptively identified in the field. This new method of presumptive field testing will benefit law enforcement, forensic laboratories, and the court system by increasing safety, decreasing costs and time, reducing the incidence of false positive results, and expediting case processing. Part of the research focused on evaluating the performance of the ReporteR device, which is manufactured by SciAps, Inc. After improvements were made in the ReporteR device, testing proved its capability for analyzing methamphetamine and cocaine. The lab also investigated the advantages of algorithm-based fluorescent baseline correction technology by integrating a Raman microscope into the research design. The microscope was used to compare results generated by the ReporteR. Methamphetamine field-testing accuracy increased 19.4 percent, and cocaine field testing accuracy increased 26.6 percent. The reliability of the ReporteR was investigated by random re-testing of samples; results were consistent in approximately 87 percent of the samples. Limitations in the use of this technology with other drugs are discussed, and suggestions for research in this area are offered. 21 figures and 46 references