Scientific and Legal Applications of Bloodstain Pattern Interpretation

Stuart H. James

• Publisher: CRC Press
• Year: 2018
• Print ISBN:
  9780849381089
• eBook ISBN:
  9781351417525
• Topic: Law
• Subtopic: Forensic Science
• Index: Law

Since 1955 when Dr. Paul Kirk first presented a bloodstain evidence affidavit in State of Ohio v. Samuel Sheppard, expert testimony on bloodstain interpretation has gained wide acceptance in U.S. courts. Scientific and Legal Applications of Bloodstain Pattern Interpretation brings together some of the most respected and noted experts in forensic science, the law, and bloodstain interpretation to provide a comprehensive overview of the discipline. It discusses research, applications, and the current view of bloodstain pattern interpretation within the legal system at the trial and appellate court levels, as well as scientific approaches and developments in the field.
Scientific and Legal Applications of Bloodstain Pattern Interpretation will help attorneys who are questioning and cross-examining expert witnesses have a good working knowledge of bloodstain interpretation. Included is a full-color atlas of bloodstains, in conjunction with a glossary of terms and an outline of basic laboratory experiments that are commonly used in the discipline.

Among the outstanding contributions in this volume you will find:

An excellent chapter by Carol Henderson discusses the legal and ethical aspects of bloodstain pattern evidence in detail.

A post-conviction analysis by Marie Elena Saccoccio evaluates how bloodstain evidence can play a role in the appeal process.

Misinterpretation and overinterpretation of bloodstain evidence can occur in our courts of law-be prepared to effectively analyze the evidence and the testimony with Scientific and Legal Applications of Bloodstain Pattern Interpretation.

1

Defining the “Address” of Bloodstains and Other Evidence at the Crime Scene¹

WILLIAM C. FISCHER

Contents

Introduction

Methodology

Two Angles and a Distance

Attributes

Orientation

Surface Designation

Establishing the Flight Path

Solving for the Slope of the Flight Path

Databasing

Solving for the Impact Angles

Solving for the Point of Intersection

Distance to the IP

Calculating the Value of the Third Coordinate

Calculating the Distance from Stain to PO

Units

Other Objects and Surfaces

Observations

References

Introduction

Acts of extreme violence often produce a dispersion of blood volumes forced from a wound site. Gunshot and other high-energy impacts, such as blunt force beatings, may disperse these blood volumes along relatively flat trajectories.

Figure 1.1

Molecular cohesion creates surface tension at the boundaries of these blood volumes. Surface tension causes the drop volumes to assume nearly spherical shapes in free flight. These drops result in bloodstain evidence being deposited on the floor, walls, ceiling, or other surfaces or objects within a crime scene.

Interpretation of the resulting stain patterns may permit an analyst to approximate the three-dimensional point of origin. This chapter develops an equation and a methodology for calculating that point.

It is a common observation that the path of a liquid drop is aligned with the long axis of the resulting stain (Figure 1.1). The flight direction of the drop is toward the tapered end of the stain. In a 1971 paper, MacDonell and Bialousz¹ demonstrated that a predictable relationship exists between the length-to-width ratio of a bloodstain and the angle at which it strikes a static surface (Figure 1.2).

$\text{IMPACT}\text{ANGLE}\text{=}\text{arcsin}\left(\frac{\text{Width}}{\text{Length}}\right)$

(1.1)

MacDonell further demonstrated that the approximate three-dimensional point of origin can be reestablished by running several tautly stretched strings. Each string is aligned with the long axis of a particular stain and angled from the surface according to th...

Table of contents

• Cover
• Title Page
• Copyright Page
• Table of Contents
• Preface
• List of Authors
• About the Authors
• Acknowledgments
• 1 Defining the “Address” of Bloodstains and Other Evidence at the Crime Scene
• 2 Bloodstain Pattern Analysis with a Computer
• 3 Utilizing Bloodstains in Accident Reconstruction
• 4 Presumptive Testing for Blood
• 5 Approach to Case Evaluation and Report Writing
• 6 Legal and Ethical Aspects of Bloodstain Pattern Evidence
• 7 Bloodstain Pattern Interpretation: A Post-Conviction Analysis
• 8 Outline of Basic Laboratory Experiments for Bloodstain Pattern Interpretation
• Bloodstain Atlas and Terminology
• Bibliography
• Appendix 1 Affidavit of Paul Leland Kirk: State of Ohio v. Samuel H. Sheppard
• Appendix 2 Illustrative Testimony — A Motion in Limine for the Admissibility of Bloodstain Pattern Interpretation
• Appendix 3 Court Decisions Relating to Bloodstain Pattern Interpretation
• Appendix 4 Court Decisions Relating to Presumptive Blood Tests
• Appendix 5 Trigonometric Tables — Sine and Tangent Functions
• Index