Bloodstain Pattern Analysis: Another Subjective “Science” Convicting Innocent People

On October 13, 1997, serial killer Tommy Lynn Sells stabbed 10-year old Joel Kirkpatrick to death in his bedroom. Joel’s mother, Julie Rea, awoke to his screams and rushed to his bedroom where Sells attacked her. She chased him, breaking two glass doors on their way out of the house, where Sells attacked her again and then disappeared into the night. Tommy Lynn Sells’ violent and heinous crimes spanned over 20 years, all over the country, with known victims’ ages spanning between 3 and 51 years of age. 

On January 2, 2000, Sells was arrested for a murder and attempted murder in Texas. At the same time, over 1000 miles away, in Lawrenceville, Illinois, Julie Rea was being investigated for the murder of her son, and 10 months later she was indicted on capital murder charges. In 2002, Julie was convicted and sentenced to 65 years for the murder of her son - on the testimony of two bloodstain-pattern analysts

Bloodstain-pattern analysis (BPA) is the analysis of blood stains, used in criminal investigations, providing information based on the size and shape of the stain. The bloodstains are interpreted by analysts to determine the distance and speed the blood traveled, the force used, the type of injury (and whether the blood was from a vein or an artery), the position of the body when the injury occurred, and any subsequent movements. 

Although medical examiners or biologists examine the characteristics of blood inside the body, when blood is analyzed outside the body the analysis is often done by bloodstain-pattern analysts. In the article “Bloodstain Pattern Analysis: A Strong Evidence for the Cause of the Miscarriage of Justice,” professors out of The University of Criminal Investigation and Police Studies in Belgrade, Serbia, found, “it is better [for bloodstain-pattern analysis] to be done by mechanical engineers or physicists because they have knowledge in the field of fluid mechanics and mathematics. When the blood moves through the air it behaves like a bullet. BPA means reconstruction of creation of blood as physical evidences and it includes measurements and calculations according to the laws of fluid mechanics.” 

Although the findings and recommendations of these professors make perfect sense, the prerequisites to become a FBI bloodstain-pattern analysis trainee are either, (1) a bachelor's degree or equivalent in a field of study related to BPA from an accredited college or university; or (2) an associate’s degree or equivalent in a field of study related to BPA from an accredited college or university and two years of job-related experience; or (3) a high school diploma or equivalent and four years of job-related experience. Job-related experience, according to the FBI, “includes, but is not limited to, experience as a: crime scene technician, criminalist, or homicide/criminal investigator.” Notably, no experience in physics, biology, medicine, or fluid mechanics is required.

The FBI training consists of a preliminary course in Fundamentals of Bloodstain Pattern Analysis, a one week Bloodstain Pattern Analysis for the Examiner course, and a one week Bloodstain Pattern Analysis for Documentation & Collection of Blood Evidence course. However, the FBI is not the exclusive administration conducting this training. There are 40 hour training courses available all over the country for law enforcement officers, by companies requiring no other prerequisites or educational backgrounds. 

This is problematic in that a detective, for example, or even a medical examiner, would not have the technical knowledge in physics and mathematics to understand fluid mechanics necessary to make a robust, credible analysis of blood’s behavior once it exits the body. With the FBI and other state or national companies producing credentialed “experts” who are then used in courts, innocent people like Julie Rea, Brad Jennings, Sam Sheppard, David Camm - and many more - can be convicted. 

In 2004, Tommy Lynn Sells confessed to the murder of Julie Rea’s son, Joel, and in 2006 Julie was exonerated thanks to the hard work of the legal team assembled by the Center on Wrongful Convictions at Northwestern University’s Pritzeker School of Law. However, if not for Sells’ confession, Julie Rea may have spent the rest of her life in prison for a crime she did not commit, based on junk bloodstain pattern analysis “science.”