Developing DNA Friendly Fluorogenic Methods for Detecting, Enhancing and Preserving Bloody and Proteinaceous Impression Evidence

As submitted by the proposer: Impression evidence, both blood and non-blood is a common component at many crime scenes. Current fluorogenic enhancement methods for impression evidence are problematic for DNA preservation and are often impractical for crime scene use. Recently developed Zar-Pro Fluorescent Blood Lifting Strips have been successful in lifting, enhancing, and preserving bloody impression evidence through the incorporation of metal-enhanced fluorescence technology. The lifting strips are durable and non-toxic, providing a highly sensitive method for processing and fluorogenically enhancing bloody impression evidence that can be preserved and utilized over long time intervals, however, the viability of subsequent DNA analyses has not be established. In addition, some evidence processing may be more suited to a spray reagent to assist in detecting impression evidence that is not readily visible, as opposed to just a lifting strip format. This project proposes an integrated two-phase approach; the first phase will develop a fluorogenic small particle reagent spray capable of enhancing and preserving bloody and proteinaceous impressions with long-term fluorescent capabilities using metal-enhanced fluorescence. The second phase will test the viability of DNA in evidence processed with Zar-Pro lifting strips and the fluorogenic small particle reagent spray then develop and optimize a DNA extraction protocol suitable for use with this technology. The goals of this project include the development of simple, time and cost effective, non-toxic methods that are safe for use at crimes scenes and provide opportunities for subsequent DNA recovery in the laboratory. Simplifying collection and preservation, while expanding the utility of the methods to include subsequent DNA analyses, has the potential to impact the future of impression evidence analysis. As an estimate of the benefit of this technology, consider the forensic casework involved in the FBI's 2011 estimated 1,203,564 violent crimes that occurred in major urban areas of the United States. ca/ncf