Identification of Bloodstain Patterns

The analysis of bloodstain patterns can be a decisive part of a forensic investigation. The patterns of bloodstains may concur with or challenge the sworn statements of witnesses, victims, and suspects. Such bloodstain patterns simply identify the source of the blood and the direction of the blood’s flight path, but during the process, the events of the crime can be reconstructed with reasonable accuracy. Unfortunately, the old method of analyzing bloodstain patterns, which uses strings, requires much time and effort. It is also subject to human error.

To reduce human error, mathematical calculations are used instead, along with a computer software program known as Back Track. Yet, a three-dimensional representation of the results of bloodstain analysis will be more convincing in any court representation. Therefore, in an effort to revolutionize this aspect of forensic investigation, a concerted effort by four researchers from three agencies, Ottawa Police Service, Carleton University and Royal Canadian Mounted Police, was conducted using the AutoCAD software. The researchers were Kevin Maloney, A. L.

Carter, Scott Jory, and Brian Yamashita. The results of their studies were reported in an article published by the Journal of Forensic Investigation, in 2005, volume 55, issue 6, and pages 711 to 725. The article attempts to demonstrate how the combined use of AutoCAD and Back Track programs can create three-dimensional representations of a bloodstain analysis. Summary and Critique The overall purpose of Maloney, Carter, Jory, and Yamashita is to explore the possibility of creating a three-dimensional representation of an analysis of bloodstain patterns.

They utilize a simulated crime scene that is typically used at the Canadian Police College. The choice of this crime scene is to have known bloodstain patterns with which the results of the combination of Back Track and AutoCAD can be compared. Both the impact angles and the glancing angles of the bloodstain trajectories were incorporated into the program. The comparison shows that the computerized calculations of virtual strings created by the Back Track program match the known location of the blood source, with an average error of six centimeters only. These results prove the precision abilities of the said software.

However, a major weakness of this study is its unquestionable reliance on the Back Track program. This program has many limitations and it was even pointed out later in 2006 by Andy Maloney (the relationship to one of the researchers is not described). For example, the Back Track is incapable of computing angled surfaces (Maloney, 2006). Yet, despite the limitations, the efficacy of using the program is grounded on established theory and supported by experimental validation (Carter, 2001). There would be expected errors but these are assumed to be insignificant in the overall investigation.

At the same time, the software is known to undergo updates and modifications. The greatest strength of this research is the launching of a better interface between the laboratory science of the forensic team and the assessment abilities of the court. The AutoCAD program has a feature that locks the virtual strings and enables any user to view them from different perspectives. The three-dimensional representation of the analysis of bloodstain patterns is, as the researchers concluded, “extremely useful in court presentation” (Maloney, et. al. , 2005, p. 724).

This article, as well as the research study that it describes, can be considered as a milestone towards a revolutionary aspect of bloodstain pattern analysis. Instead of numbers presented in tabular form or in picture graphs, the results of the analysis can be presented in three dimensions. In three dimensions, the court presentation becomes more realistic, more convincing, and more enlightening, such that the jury can make better assessments. But this article, as far as the advances in forensic science in general and in bloodstain pattern analysis in particular go, can be considered somewhat obsolete.

There are now new software or computer programs that can be utilized to produce the same three-dimensional results (Kanable, 2006). This means that in conducting an analysis of bloodstain patterns, a forensic investigator has other options, aside from the combined use of the Back Track program and the AutoCAD. But this wider range of technological tools does not detract from the greatest significance of this article. This article, in great detail and with diagrams, shows how the observed and calculated data are translated into three dimensions. Thus, this article is a recommended reading for every forensic science student.

Bibliography Carter, A. L. (2001). The directional analysis of bloodstain patterns theory and experimental validation. Canadian Society of Forensic Science, 34 (4), 173-189. Kanable, R. (2006). HemoSpat: New bloodstain pattern analysis software to hit the market. Law Enforcement Technology, August issue. Retrieved September 28, 2007 from the website of Officer. com at http://www. officer. com/publication/article. jsp? pubId=1&id=32890 Maloney, K. , Carter, A. L. , Jory, S. , & Yamashita, B. (2005). Three-dimensional representation of bloodstain pattern analysis. Journal of Forensic Identification, 55 (6), 711-725.