Originally posted by Fisherman
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Q. I would like to talk about another victim Polly Nichols she was found murdered with her throat cut and some minor abdominal mutilations. It has been suggested that the person who found the body could have been her killer, as it was reported that blood was still flowing from the throat wound, and the body was still warm 30 minutes later when the doctor examined the body at the scene. Could a body with these injuries bleed from a neck wound for more than twenty minutes?
A. I think it is certainly possible that ‘bleeding’ could go on for a period of twenty minutes, although I would make a distinction between ‘post mortem leakage of blood from the body’ and actual ‘bleeding’ that occurred during life. The flow of blood is likely to have slowed to a trickle by this time as the pressure inside the vessels would have dissipated and the volume of blood remaining available to leak out would have become very little.
In many cases, the majority of the blood found at the scene may have seeped out of the veins. This can happen under the influence of gravity, and therefore, is not dependent on a beating heart (i.e. blood can continue to seep out for quite some time after death). As long as there is still blood throughout the body it can theoretically still leak out under gravity, so there could be a period of several minutes where blood continues to flow after an injury (including after death... it is not unusual for a body that has been dead for some time to ‘bleed’ from a knife wound when you start moving it).
This is likely to be minimal (almost negligible) in nature, as the majority of the blood that could come out would have done so much sooner. If a witness discovered a body that was still bleeding relatively profusely, then the injuries are likely to have been inflicted more recently than 20 minutes previously... but if the 20 minute period is critical in ruling out / in certain suspects, then I wouldn’t dismiss the possibility of some continued blood loss at this time, as I think, it would be possible. (I base this on my own observations of seeing blood leak out of bodies when I have been present at murder scenes some hours after death. This is why I am open to many things being ‘possible’, even though I can’t state categorically what ‘would’ or ‘would not’ have happened in an individual case.)
Q. To what extent would the position of the neck have had an impact on bleeding from such a wound?
A. The position of the neck could potentially influence the rate of flow of blood in that it could either ‘hold open’ or ‘squeeze shut’ various vascular injuries. In practice, if the neck was injured almost to the point of decapitation, then there might be little in the way of a ‘clamping’ effect possible no matter how the neck is angled. In simple terms, nasty neck wounds can bleed a lot (but don’t always). Blood can leak out after death (and for quite some time). You can’t tell anything about the time of injury/death by assessing the blood loss at the scene.
The short answer is that ‘a lot’ of blood would be lost from neck wounds such as this..., but the exact volume could vary greatly depending upon individual circumstances. In terms of time, there would be an initial rush of blood, but the victim’s blood pressure would rapidly subside (in a matter of seconds if the blood loss is particularly profuse) so that the rate of flow would become considerably less relatively soon after injury. After the circulation has stopped, it will be down to gravity to continue the blood loss, and clearly, this will depend on position/angle and so on.
Sometimes a wound will be ‘propped open’ by the position of the body, whereas in other cases the wound may be ‘squeezed shut’ by the weight of the body.
Things like vessel spasm and rapid clotting can be surprisingly good at staunching the flow of blood from even very catastrophic injuries. Even if a person is lying such that their injury is gaping open and is ‘down’ in terms of gravitational direction, this does not necessarily mean that blood will continue to flow out until the body is ‘empty’. Things like collapsing vessels and valve effects can prevent this passive flow, and there are lots of ‘corners’ for the blood to go around (it is spread around lots of long thin tubes, not sitting in a large container) before it finds its way out of the injury... so it might end up ‘trapped’ within the body. I have certainly seen cases with multiple large knife wounds and copious blood at the scene, where a significant proportion of the victim’s blood has remained within the vessels to allow me to obtain good samples for toxicological analysis later in the mortuary.
Getting back to the specific case in question, if the body were lying motionless on the ground with significant open neck wounds, then I would imagine that at least a few hundred millilitres (and probably considerably more) could flow out passively and that this would happen within an initial couple of minutes. If this doesn’t sound like a lot, remember that a little blood can look like an awful lot when it is spilt onto the pavement. For the reasons mentioned above, it would be possible that a lot less blood would be apparent at the scene. It is also possible that a continued slow trickle could go on for many minutes after death if the wound/gravity conditions were right, ending up with even a few litres of blood being present in extreme circumstances.
I did an autopsy last week, where the body had been transported a great distance to the mortuary, and death had occurred almost 24 hours before my examination... and yet the injuries continued to ‘bleed’ relatively profusely for quite some time. So much so that we struggled to get a ‘clean’ photograph as the blood flooded back as quickly as we could wipe it away! This is why I have been cautious about commenting on ‘maximum’ timings and quantities of blood loss.
Q. Would the wounds to the stomach have an impact on how long it took for her to bleed out?
A. Severe abdominal wounds would ‘contribute’ to the rapidity of bleeding to death, but this effect could range from almost negligible (if the neck wounds were so bad that death would have been very quick, and the abdominal wounds didn’t hit anything major) to be very great (if the neck wounds miraculously missed all the major vessels, and the abdominal wounds pranged something big).
There is nothing about blood flow from a wound that will help estimate the time of death. Dried blood on the skin can indicate the position of the body relative to the direction of gravity, but that’s about it.
Basically your theory is shot to pieces in more ways than one and a definate non starter, but fair play to you who has continued to stand by what you belive to be the truth

www.trevormarriott.co.uk
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