An Approach for the Visualization of Particle Spread During the Handling and Analysis of a Drug Evidence

Abstract

Recent work has shown that detectable levels of drugs exists on nearly all surfaces within the forensic laboratory – especially within the drug chemistry unit. This is an expected occurrence due to the handling and opening of drug evidence that contains powder material. The process of opening of evidence for analysis is believed to be one of the main contributors to the background levels as it produces aerosolized particulate that will settle on surfaces throughout the lab. This process, however, has never been visualized. This work presents the first attempt to visualize the spread of particulate throughout the laboratory during the analysis of drug evidence. By creating two simulated bricks of heroin that contained fluorescent particles, the spread of particulate was able to be monitored throughout the evidence handling process up to and including cleaning of surfaces after analysis. The spread of particulate was shown to be quite extensive, and transfer onto unexpected surfaces was observed. Cleaning with methanol after processing the evidence was shown to be effective at removing nearly all particulate that was released in the process. The use of visualization techniques such as this show promise for helping to identify processes that may contribute to drug background levels in the laboratory as well as provide methods to inform practitioners how trace residues spread.