Armchair Detective: Bloodstain Sequencing
As I’ve written before, the examination of bloodstain patterns can be crucial in reconstructing the events of a crime. Blood is fluid and thus can be influenced by the actions of bleeding subjects and others in contact with wet blood. As a general rule; the more blood present the more we may be able to tell about the actions and events comprising the commission of a crime. Make no mistake though, this is very difficult stuff to analyze. I’ve spent over a decade studying bloodstain patterns with some of the best practitioners in the world. It may seem simple and straightforward but there is a lot more to consider than just the bloodstain patterns. For now, let’s just look at a simple exercise of recognition and sequencing. You don’t need any background information for the photo in order to conduct this exercise. Assume all of the blood seen is from the same individual. I’m not going to tell you the cause or manner of death. Focus on the blood and rely on your common sense.
Take a look at the photo and try to figure out two main actions taking place. Keep it simple. The more detail you try to discern the more inaccuracy you’ll probably create (unless of course you’re a professional). In the end, see if you can sequence any of the events you’ve described. If you could ask only one question what would it be?
Well, I was hoping for a few more responses but perhaps this one was too difficult? For those that are interested here are a few main observations. Notice the large pool of blood (the darker red horizontal area). That indicates that the victim was laying near that position for some period of time (as opposed to walking through or running by). Then, do you see how that blood is separated into two halves (larger one on the left, smaller on the right) with a lighter ares cutting through at about the center of the photo? That particular pattern is repeated directly above it. Now look to the right against the wall. You should see two bloody right hand impressions (palm and finger tips on the right side of the blood pool). What these two types of marks indicate is that the victim crawled through the blood pool on his hands and knees. Can you envision that? These patterns taken together indicate (generally) that the victim was injured (to produce external bleeding) then collapsed on the cement where he bled to produce a large pool for an undetermined amount of time. Then after that he became mobile again and crawled through the blood which had already congealed (this is why the two pools remained separated). Now there is a ton more going on but it won’t make much sense without understanding all of the case details which I won’t go into but, I hope you can see that the analysis of bloodstains can reveal important clues at the crime scene. If I were to ask one additional question it would be about the condition of the victim’s clothing, specifically the knees (and hands) which should both be bloodstained if they produced these marks.
Posted on August 28, 2012, in The Armchair Detective and tagged Bloodstain Pattern Analysis, BSPA, Crime Scene, csi, fiction, forensics, murder, mystery, police, thriller, tom adair. Bookmark the permalink. 4 Comments.