Warning, this blog isn’t for the faint hearted!
The definition of Projected patterns is a result from the ejection of blood under pressure. These stains are normally found where an artery has been punctured and the subject has moved around the scene. They are a good sight for a CSI, but a bad one as a human, as you then realise someone may have been seriously injured. I see these patterns more often at stabbing and serious assault scenes than your typical high street scuffle.
During a training course we carried out some exercises so we could see what Projected patterns looked like on various surfaces, both vertically and horizontally. We used a syringe and ejected the blood onto the different surface types. On a smooth wall they look rather nasty; blood will often run down the wall following gravity, leaving a rather sinister look.
Blood was ejected onto both carpet and paper. Where the carpet is more absorbent the pattern is more contained than on paper, where ‘spines’ and ‘satellite stains’ were found (refer to previous blog).
The biggest difference between the horizontal and vertical surfaces is the lack of those sinister flow patterns running down the wall, which are obviously not seen on the floor. However you still can see a fine line of blood in both, and this is how I notice these patterns on each surface.
Further to my previous blog where blood was found in a kitchen, the assault between the two males then continued upstairs in a bedroom. Blood was found on the carpet which appeared consistent with a Projected pattern, especially in the bottom right corner of the image where the blood loops around. This suggests that someone was suffering with a nasty incision/laceration which likely hit an artery whilst in the room.
These patterns can sometimes give you an idea of the direction of travel the depositor is going. By gaining information from the hospital, or sadly the mortuary, regarding the injuries sustained can help piece together bloodstains at the scene. For example, if a victim has sustained injuries to an artery on their right side, blood would have a higher chance of being deposited to their right. If you were looking down a hallway and a Projected blood pattern was on your right, the depositor was likely walking down the hallway (away from you).
Projected patterns are one of many different blood patterns I found at this assault scene. I aim to continue writing about different patterns I found. Stay tuned!