Peer-Reviewed News

This information has been subjected to peer review and has been published in a recognized journal or periodical. This information contains relevant cites that pertain to footwear, tire or barefoot impression evidence. Other peer-reviewed information that may be indirectly related to the aforementioned forensic disciplines (e.g., legal or enhancement techniques), may also be posted here.

Forensic Identification Science Evidence Since Daubert: Part I—A Quantitative Analysis of the Exclusion of Forensic Identification Science Evidence

Page, M., Taylor, J. & Blenkin, M. (2011). Forensic Identification Science Evidence Since Daubert: Part I—A Quantitative Analysis of the Exclusion of Forensic Identification Science Evidence. Journal of Forensic Sciences, 56 (5), 1180–1184.

Abstract

The U.S. Supreme Court decisions in Daubert v. Merrell Dow Pharmaceuticals Inc. and Kumho Tire Co. Ltd. v. Carmichael transformed the way scientific expert evidence was reviewed in courts across the United States. To gauge the impact of these rulings on the admission of forensic identification evidence, the authors analyzed 548 judicial opinions from cases where admission of such evidence was challenged. Eighty-one cases (15%) involved exclusion or limitation of identification evidence, with 50 (65.7%) of these failing to meet the “reliability” threshold. This was largely because of a failure to demonstrate a sufficient scientific foundation for either the technique (27 cases) or the expert’s conclusions (17 cases). The incidence of exclusion/limitation because of a lack of demonstrable reliability suggests that there is a continuing need for the forensic sciences to pursue research validating their underlying theories and techniques of identification to ensure their continued acceptance by the courts.

Chemical Enhancement of Footwear Impressions in Urine on Fabric

Kevin J. Farrugia, Helen Bandey, Steve Bleay and Niamh NicDaéid. Chemical enhancement of footwear impressions in urine on fabric. Forensic Science International. Available online 2 August 2011.

Abstract

A range of chemical techniques were utilised for the enhancement of footwear impressions deposited on a variety of fabric types of different colours with urine as a contaminant. A semi-automated stamping device was used to deliver test impressions at a set force to minimise the variability between impressions; multiple impressions were produced and enhanced by each reagent to determine the repeatability of the enhancement. Urine samples from different donors were analysed using a spectrofluorophotometer revealing differences between individuals. Results indicated that the enhancement of footwear impressions in urine was possible using amino acid staining techniques whereas protein stains failed to achieve successful enhancement.

Wet Powder Suspensions as an Additional Technique for the Enhancement of Bloodied Marks

Au, C., Jaskson-Smith, H., Quinones, I., and Daniel, B. Wet powder suspensions as an additional technique for the enhancement of bloodied marks. Forensic Science International. 2011; 204 (1): 13-18. Available online May 24, 2010.

Abstract

The enhancement of marks in blood on dark surfaces poses significant challenges to the forensic scientist. Current methods of enhancement include the sequential use of acid dyes (acid yellow, acid violet and acid black). Acid yellow is used to greatest effect on lighter deposits of blood on a non-porous background, and is visualised using a light source which causes it to fluoresce [1]. However, further enhancement with acid violet and acid black produces a dark product which may fail to improve the contrast of the mark against a dark background.

The use of wet powder suspensions (WPSs) has been proposed as a complementary procedure for use in fingermark enhancement, beyond its typical use in the enhancement of marks on adhesive surfaces.

In this investigation, the use of WPS was tested in conjunction with conventional acid dye treatments on marks in blood deposited on a selection of substrates.

The results demonstrated that white WPS alone or together with acid dyes results in an overall enhancement of mark quality (p<0.005) on marks deposited on smooth non-porous surfaces.

The technique was shown to not interfere with subsequent presumptive tests on blood. However WPS treatments were shown to reduce the amount of DNA recoverable from the marks, resulting on an average decrease of 91% compared to untreated controls. The decline in DNA yields was shown to result in a decrease in the quality of the DNA profiles obtained.

The enhancement properties of WPS were evaluated by electron microscopy. It was shown that the titanium dioxide particles in the WPS primarily interact with the non-bloodied part of the mark, thus producing a contrasting effect with the background and acid dyes.