NCJ Number
196834
Journal
Journal of Forensic Identification Volume: 52 Issue: 5 Dated: September/October 2002 Pages: 579-593
Date Published
September 2002
Length
15 pages
Annotation
This research identified five physical characteristics of swipe patterns in bloodstain pattern analysis, along with their orientation in relation to direction of motion.
Abstract
Although the method for determining direction of motion for swipe patterns is discussed in numerous references, these methods have not been previously studied for verification and validity. In the field of bloodstain pattern analysis, a "swipe" generally contains the following elements: the transference of blood from a bloodied object to a secondary unstained surface through contact with lateral movement of some nature between the two objects. Swipe patterns are often pattern transfers as well, showing specific characteristics of the object causing the swipe. This article describes the procedure used to answer the following questions: What specific physical characteristics are present in swipe patterns? Do these characteristics appear in any specific orientation when correlated with the direction of motion in the swipe? Are any of these characteristics (individually or in some combination) reliable as indicators of direction of motion of the swipe? Using the orientation of five identified swipe characteristics, the study found that determination of direction of motion is possible in some swipe patterns. The recurring pattern evident across all surfaces was the presence of the irregular demarcation on the contact side, accompanied by the presence of one or more of the four other characteristics (feathered demarcation, striations, diminished volume, welling) on the departure side of the stain. Determination of motion was not always possible. This was particularly so in situations in which both departure and contact edges shared common characteristics (e.g., both have irregular demarcation). In such instances, determination of the direction of motion should not be attempted. 5 figures, 3 tables, and 6 references