Chemical Enhancement Techniques of Bloodstain Patterns and DNA Recovery After Fire Exposure

• NCJ Number: 225886
• Journal: Journal of Forensic Sciences Volume: 54 Issue: 1 Dated: January 2009 Pages: 37-48
• Author(s): Karolyn L. Tontarski M.S.; Kyle A. Hoskins B.S.; Tani G. Watkins B.A.; Leanora Brun-Conti B.S.; Amy L. Michaud B.S.
• Date Published: January 2009
• Length: 12 pages
• Publication Format: Article
• Publication Type: Report (Study/Research)
• Language: English
• Country: United States of America

Annotation

This study examined whether or not bloodstain patterns could remain unaltered and therefore interpretable after exposure to a fire and subsequent efforts to extinguish the fire, as well as whether currently used chemical enhancement techniques assisted in the visualization of the patterns.

Abstract

The study found that the majority of bloodstain patterns were observable under bright light following the fire. Accordingly, bloodstain patterns are interpretable after a fire, depending on the extent of damage caused by the fire and firefighting efforts. Bright light should be used initially in an attempt to locate bloodstain patterns that have not been burned away by the fire. All chemical enhancement techniques used on the bloodstains were successful; however, due to the sooty conditions, it was easiest to photograph the positive fluorescein results and avoid overdiluting the stains. The luminol and Bluestar required additional amounts of reagent than is normally required in order to achieve a positive result. When attempts were made to remove soot from the bloodstains by using water and 70 percent isopropanol wipes, the chemical enhancements gave positive results quicker than when having to penetrate the soot. Unless excessive amounts of soot were present, there were no difficulties when using either a chemical enhancement technique or the Hemastix test strips. None of the chemical enhancement reagents interfered with obtaining a DNA profile. Suggestions for future research are offered. The study involved the creation of a variety of known types of bloodstain patterns in a four-room structure that contained typical household objects and furnishings. The structure was allowed to burn to flashover before firefighters extinguished it with water. Once the structure cooled over night, the interior was examined with a bright light. The chemicals used to enhance visualization of the stains were fluorescein, luminol, Bluestar, and Hemastix. 8 figures, 7 tables, and 21 references