The impact of packaging and transportation on the analysis of level two details in latent prints

Abstract

This study was conducted to determine if packaging and transportation of small items of evidence impacts the ability to preserve and process latent friction ridge impressions deposited on those items. Similar research has been completed with DNA evidence and researchers found that packaging and transportation did impact the quality of the DNA evidence when it was analyzed (Goray et al., 2012). As latent prints are fragile, assessing current practices and determining the best protocols for latent print recovery is essential. This study focused on best methods for preserving and processing latent friction ridge impressions. Aluminum cans and ceramic white tiles were used as items of evidence. Fingerprints were deposited on the items and left for two hours to represent time between the crime being committed and the same crime being investigated. The evidence was then divided into two groups – one group processed without being transported and one group processed after being packaged in paper bags and driven in the car. These two groups represented evidence processed on scene and evidence processed after being packaged and taken to the lab. Time of transport was 30 minutes. Latent impressions were then processed with black powder and the prints were lifted with tape. Latent impressions were analyzed for level 1 detail (cores, deltas, pattern type) and level 2 detail (ending ridges, bifurcations, dots, etc.). The value of the friction ridge detail was then compared between the items processed on scene and those items of evidence that were transported. The goal of this study was to establish best practices and guidelines for preserving and processing latent friction ridge impressions in an effort to maintain the highest possible level of detail and provide more value during the analysis phase. It was determined that the substrate the fingerprints are deposited on heavily influences how the fingerprints will be affected by the packaging. The fingerprints on the ceramic tiles had less frequent contact with the inside of the packaging, but were more affected when contact did occur. The aluminum cans had more frequent contact with the inside of the packaging, but were less affected.