In some cases, the bloodstain pattern analyst can't actually visit the crime scene. He must rely on investigators and technicians to take long-range, medium-range and close-up photographs of each spatter using an indication of scale. The technician must also make sure to note the orientation of the spatter in relation to other elements of the scene, such as furniture. Later, the analyst views all of the photographs to draw conclusions. If adequate photos aren't taken, bloodstain pattern analysis can't happen. Emergency technicians and law enforcement officers can sometimes change or destroy blood spatter evidence, so analysts have to recognize things like shoeprints left by a police officer stepping in the victims' blood.
History of Blood Spatter Analysis
Although bloodstain pattern analysis has been studied since the late 1890s, investigators haven't always recognized how valuable it can be. The first known study of blood spatters occurred at the Institute for Forensic Medicine in Poland, by Dr. Eduard Piotrowski. He eventually published the book "Concerning the Origin, Shape, Direction and Distribution of the Bloodstains Following Head Wounds Caused by Blows." Cases that included the interpretation of blood spatters didn't appear until 50 years later.
In the highly publicized case of the State of Ohio v. Samuel Sheppard, an affidavit concerning blood spatter evidence was entered by Dr. Paul Kirk. This 1955 case marked one of the earliest instances of the legal system recognizing the importance of blood spatter analysis. Dr. Kirk showed the position of the assailant and the victim as well as showing that the assailant struck the victim with his left hand.
The next significant person in the field was Dr.Herbert MacDonell, who published "Flight Characteristics of Human Blood and Stain Patterns" in 1971. MacDonell also trained law-enforcement in blood spatter analysis and developed courses to continue to train analysts. In 1983, he and other attendees of the first annual Advanced Bloodstain Institute founded the International Association of Bloodstain Pattern Analysts (IABPA). Since then, the field of bloodstain analysis has continued to grow and develop. It has now become standard practice for law enforcement to include during crime-scene investigation.
One infamous case that comes to the mind of many people when thinking about blood spatter analysis also includes a line that became a catchphrase (thanks to Meryl Streep in the movie "A Cry in the Dark" and Elaine Benes on "Seinfeld"): "The dingo ate my baby." We'll explore that story on the next page.