U.S. flag

An official website of the United States government, Department of Justice.

NCJRS Virtual Library

The Virtual Library houses over 235,000 criminal justice resources, including all known OJP works.
Click here to search the NCJRS Virtual Library

Reliability of Pattern Classification in Bloodstain Pattern Analysis, Part 1: Bloodstain Patterns on Rigid Non-absorbent Surfaces

NCJ Number
249866
Journal
Journal of Forensic Sciences Volume: 61 Issue: 4 Dated: April 22, 2016 Pages: 922-927
Author(s)
Michael C. Taylor; Terry L. Laber; Paul E. Kish; Glynn Owens
Date Published
July 2016
Length
6 pages
Annotation
This study was designed to produce the first baseline measure of reliability in bloodstain pattern classification.
Abstract
A panel of experienced bloodstain pattern analysts examined over 400 spatter patterns on three rigid non-absorbent surfaces. The patterns varied in spatter type and extent. A case summary accompanied each pattern that either contained neutral information, information to suggest the correct pattern (i.e., was positively biasing), or information to suggest an incorrect pattern (i.e., was negatively biasing). Across the variables under examination, 13 percent of classifications were erroneous. Generally speaking, where the pattern was more difficult to recognize (e.g., limited staining extent or a patterned substrate), analysts became more conservative in their judgment, opting to be inconclusive. Incorrect classifications increased as a function of the negatively biasing contextual information. The implications of the findings for practice are discussed. (Publisher abstract modified)