NCJ Number
236182
Journal
Journal of Forensic Sciences Volume: 56 Issue: 5 Dated: September 2011 Pages: 1136-1142
Date Published
September 2011
Length
7 pages
Annotation
An experiment was designed to explore the underlying mechanisms of blood disintegration and its subsequent effect on area of origin (AO) calculations.
Abstract
Blood spatter patterns were created through the controlled application of pressurized air (20-80 kPa) for 0.1 msec onto suspended blood droplets (2.7-3.2 mm diameter). The resulting disintegration process was captured using high-speed photography. Straight-line triangulation resulted in a 50 percent height overestimation, whereas using the lowest calculated height for each spatter pattern reduced this error to 8 percent. Incorporation of projectile motion resulted in a 28 percent height underestimation. The AO xy-coordinate was found to be very accurate with a maximum offset of only 4 mm, while AO size calculations were found to be two- to fivefold greater than expected. Subsequently, reverse triangulation analysis revealed the rotational offset for 26 percent of stains could not be attributed to measurement error, suggesting that some portion of error is inherent in the disintegration process. (Published Abstract)