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Accessing the Probative Value of Physical Evidence at Crime Scenes With Ambient Mass Spectrometry and Portable Instrumentation

NCJ Number
248884
Author(s)
Christopher C. Mulligan; Adam E. O'Leary
Date Published
May 2015
Length
141 pages
Annotation
In order to facilitate efficiency in evidence analysis in crime labs, the goal of this project was to create a broadly applicable, portable chemical detector based on a state-of-the-art mass spectrometer (MS) capable of sampling externally generated ions at a crime scene.
Abstract
The project developed and delivered a Flir Systems AI-MS 1.2 prototype with optimized instrumental method to the funder (National Institute of Justice) for evaluation and testing, along with appropriate operational documentation and a comprehensive spectral library. This capability enables the use of novel "ambient" ionization methods that allow direct screening of target compounds or "analytes" in their native environment and state without prior preparation. Ambient ionization techniques coupled to this portable system performed well when analyzing complex samples (i.e., bulk powders, chemical residues in latent fingerprints pharmaceutical tablets, clandestine synthetic reaction products/apparatus, etc.,), as well as authentic evidentiary seizures, and emerging threats. Base and tandem MS spectra obtained on the AI-MS 1.2 were marked by high congruency to that collected or reported on lab-scale, commercial MS systems, showing high potential for adoption as an accepted technique in crime-scene investigation and forensic analyses. In addition, automated library searching via data-dependent scanning and chemical identification via MS/MS fragmentation spectra offers the potential for use by non-technical operators, thus reducing the need for spectral interpretation by the end-user. 12 figures, 22 tables, 38 references, and a listing of publications that have disseminated the research findings