Method for combined biometric and chemical analysis of human fingerprints.

Jessica L Staymates,Shahram Orandi,Matthew E Staymates,Greg Gillen

doi:10.1007/s12127-014-0148-6

Abstract

This paper describes a method for combining direct chemical analysis of latent fingerprints with subsequent biometric analysis within a single sample. The method described here uses ion mobility spectrometry (IMS) as a chemical detection method for explosives and narcotics trace contamination. A collection swab coated with a high-temperature adhesive has been developed to lift latent fingerprints from various surfaces. The swab is then directly inserted into an IMS instrument for a quick chemical analysis. After the IMS analysis, the lifted print remains intact for subsequent biometric scanning and analysis using matching algorithms. Several samples of explosive-laden fingerprints were successfully lifted and the explosives detected with IMS. Following explosive detection, the lifted fingerprints remained of sufficient quality for positive match scores using a prepared gallery consisting of 60 fingerprints. Based on our results (n = 1200), there was no significant decrease in the quality of the lifted print post IMS analysis. In fact, for a small subset of lifted prints, the quality was improved after IMS analysis. The described method can be readily applied to domestic criminal investigations, transportation security, terrorist and bombing threats, and military in-theatre settings.

Highlights

Friction ridge skin impressions, or latent fingerprints, are an extremely important piece of trace evidence often discovered at the scene of a crime
If a fingerprint lift was falsely matched to a known print both before and after chemical analysis, no changes were observed as a result of chemical analysis and it was considered a neutral case
The results of this study show the feasibility of lifting a latent fingerprint using this novel method and chemically analyzing it immediately without destroying the lifted print

Summary

Introduction

Latent fingerprints, are an extremely important piece of trace evidence often discovered at the scene of a crime. Each person has unique fingerprints, and people can unintentionally leave detailed impressions of these friction ridges specific to their fingers on the objects they touch. Such latent fingerprints are often developed, photographed, and collected at the crime scene, and the images are later compared to known prints for a possible identification match [10]. IMS is a rugged and portable technique that can be used immediately at a crime scene or in theatre to detect contraband substances such as narcotics and explosives [13]. The wipe is inserted into the instrument and heated to temperatures exceeding 200 °C to thermally desorb the volatile analytes, and after a

Methods

Results

Conclusion