Multiple Contacts of Drug Contaminated Fingermarks and Their Analysis with Raman Microspectroscopy

This thesis research aimed to determine if substrate, enhancement technique, and multiple contacts affect the detection and identification of drugs in fingermarks using Raman Spectroscopy. It has the potential to be of great importance in forensic science as fingermarks are one of the most important traces left behind at crime scenes and illicit drugs are a significant criminal justice problem. Thus, being able to associate illicit drugs with a specific fingermark has great potential for forensic science, as it can put the drugs in the hands of a specific individual. The ridges of fingerprints trap trace amounts of material that result from exchanges between the individual and any surface. When individuals handle illicit drugs, these materials can be transferred and subsequently detected on their hands and fingers, as well as in the fingermarks they leave behind. Understanding the limits of detecting illicit drugs on various substrates and after multiple contacts, as well as after enhancement and collection, can provide valuable information which can be employed in forensic casework where the individuals are suspected of handling illicit substances. In addition to identification purposes, a fingermark could be used for identifying the drug component, thus aiding forensic scientists two-fold. Previous studies have been conducted on the spectroscopic analysis of drug contaminated fingermarks, however, these projects have only detected the parent drug from a single, secondary transfer. For this research, multiple contacts were taken from 10 participants that planted 15 or 20 successive drug-contaminated fingermarks on a series of 3 different substrates with specific enhancement techniques that are most commonly seen at crime scenes. Benchtop Raman Microspectroscopy and Portable Raman Spectroscopy were employed to assess the number of successive contacts from which drug contaminated marks can be detected and identified from different substrates after enhancement and lifting techniques are performed. Using Benchtop Raman Microspectroscopy cocaine was able to be identified in at least 15 contacts among all substrates tested. Further, cocaine can persist through multiple contacts even after development of the fingermarks even with variability between individuals. However, contamination of fingermarks was observed from powder brushes that were utilized. Although detection was possible using powder enhancement, it is not advisable due to the possibility of contamination