could any1 please give me some scenarios (real or fake) where the drying time of a blood stain could be of relevance? or just explain the relevance of the need to know the drying time of a blood stain
i have 1 example -
if a crime was committed, e.g stabbing, and a spot of the victims blood was found on a suspect, the suspect could argue that the spot of blood occurred at 10am and was due to an altercation with the victim but the suspect did not stab the victim as the victim was stabbed at 1pm and the spot of blood occurred earlier than the stabbing happened.
I should start by stating that I cannot recall ever having been involved in the investigation of a crime where blood drying times was relevant, or where other evidence types had more evidential value.
I steer clear of such areas as freshness of a blood stain or latent fingerprint from its appearance, there are so many physical and environmental variables to take into consideration.
So, a fake scenario...
- a footwear mark in pool of blood (next to a murder victim) that has subsequently dried. Owner of said footwear (possible suspect) states that they found the body an hour before and must have stepped in the blood at that time. Another person, who was with the suspect at time of discovery, also walked around the scene before the police attended yet does not have blood on their footwear that 'went on wet' and has not left any footwear marks in the dried blood.
If it could be shown that the blood had dried before the body had been discovered, it could indicate that the suspect must have been near the body prior to 'finding' it.
While researching the Occhi case, I had a question about the pool of blood in the hallway. The Mom left to go to work at 7:40 and by 9:30 or so the crime was detected and the bllod pool was fresh without a "skim" or hardening. Could the Mom have actually committed the crime before she left for work and the blood remain fresh looking? Also the crime scene appeared to have had someone attempt to clean up in the bathroom. If the perp was a stranger, why clean up at all? Body missing and never found.
I have tried to get info about how long blood takes to dry or harden, to no avail.
There's another case that is getting ready to be brought to trial again for the third time. It is the David Camm case out of Indiana. David was convicted twice but the convictions were thrown out; however, there is still evidence to bring to trial for a third time. Anyway, you can get the scoop on this case by looking up "Murder on Lockhart Road" on you tube. It was basically a battle of the bloodstain experts. Five experts stated that the small stains in "Area 30" on David's t-shirt were from transfer, while the other five stated they were from high velocity back-spatter. But my point is if you look at the video and/or pictures on the net you will notice a long stream of serum which separated from a pool of blood belonging to Kim Camm. It makes one wonder how long it took for the blood to do this, along with comparing it to witness testimony. It was at first believed to be some type of cleaning agent. I believe the drying times and clot retraction/serum separation times may have shed some light on this case.
Lots of research in BPA, with very good quality images (that shoemark in blood is the same pattern as one I am currently 'following' around crime scenes - you've not been to England recently have you Michael?? ;o)
There's enough work there to get a diploma from NPIA!
No, I've never been to England but would like to have the chance to visit. Thank you for your kind comment about the website. For the record, I didn't hide my link. It was put there intentionally for those who might share an interest in this discipline.