NCJ Number
223661
Journal
Journal of Forensic Identification Volume: 58 Issue: 4 Dated: July/August 2008 Pages: 453-468
Date Published
July 2008
Length
16 pages
Annotation
This study presents an innovative and improved alternative to current manual bloodstain measurement methods, using Microsoft Office Excel 2003 AutoShape functions.
Abstract
This two-step preliminary study shows that--for the bloodstain-pattern analyst using physical processes (e.g., the string line or tangent methods) in order to establish a blood-source area of origin within three-dimensional space--the fitting of an ellipse using the Microsoft Office Excel 2003 AutoShape function produces a more accurate and precise estimate of the blood-droplet alpha angle than the current manual measuring processes. Further, with images of appropriate photographic quality, small spattered bloodstains can now be measured with confidence. The inclusion of automated features (e.g., stain long axis line, stain width gridlines or box, and the symmetrical elongation of the fitted ellipse) augment the performance of the method. The Excel AutoShape function proved robust even upon first exposure to participating analysts, and there is the potential for improvements in measurement accuracy and precision following repeated exposure and familiarity. Image management and enhancement functions available in Excel allow the analyst to maximize the quality of any bloodstain image and also generate saveable, reviewable, and auditable electronic case files for each of the bloodstains measured. A laptop computer integrated with digital image capture and transfer capabilities allows the bloodstain pattern analyst to complete the Excel AutoShape measurement process at the scene. In order to make a preliminary examination of the general usefulness of the AutoShape tool for measuring bloodstains, a two-step study that involved a concept measurement survey and comparative data analysis was undertaken. 2 tables, 5 figures, and 18 references