Monday, March 12, 2012

Blood Evidence

MCCAUSLAND: Again, asking for more specifics, Nancy, that I can`t get into. But you are correct, some of the blood was visible. Some of it was detected by Luminol. And that is some of the evidence that we seized from that home along with hundreds of other pieces.

"We felt it was important that the public understand some specifics of the investigation. We felt it was important that the public understand the magnitude of this investigation and that some of the blood was Ayla's," he said. -Stephen McCausland

 
The blood evidence; it has been talked about and debated. Is it relevant to the disappearance of Ayla?

Blood in a body varies based on age, weight, sex, etcetera. An average amount of blood in a human weighing about 180 lbs. is 5.5 Liters or 23.3 cups. In a child weighing 80 lbs., the average amount of blood is 2.75 Liters or 11.6 cups and in an infant weighing 8 lbs. the average amount of blood is 8 oz or 1 cup. Based on these values, with Ayla weighing 30 lbs she would have an average of about 1 Liter of blood or about 4.2 cups.

*For people to visualize how much blood is in a Liter, I converted to cups.

A healthy person can lose about 10-15% of the total blood volume without serious medical difficulties. There are different classifications of blood loss:

Hemorrhaging is broken down into four classes by the American College of Surgeons'
Advanced Trauma Life Support (ATLS).

  • Class I Hemorrhage involves up to 15% of blood volume. There is typically no change in vital signs and fluid resuscitation is not usually necessary.
  • Class II Hemorrhage involves 15-30% of total blood volume. A patient is often tachycardic (rapid heart beat) with a narrowing of the difference between the systolic and diastolic blood pressures. The body attempts to compensate with peripheral vasoconstriction Skin may start to look pale and be cool to the touch. The patient may exhibit slight changes in behavior. Volume resuscitation with crystalloids (saline solution or Lactated Ringer‘s Solution) is all that is typically required. Blood transfusion is not typically required.
  • Class III Hemorrhage involves loss of 30-40% of circulating blood volume. The patient's blood pressure drops, the heart rate increases, peripheral hypoperfusion (shock), such as capillary refill worsens, and the mental status worsens. Fluid resuscitation with crystalloid and blood transfusion are usually necessary.
  • Class IV Hemorrhage involves loss of >40% of circulating blood volume. The limit of the body's compensation is reached and aggressive resuscitation is required to prevent death.
This classification is basically the same as used in the staging of hypovolemic shock or desanguination (massive blood loss).

So we can say that a child like Ayla could safely lose 0.15 Liters or 0.6 cups of blood without any life threatening symptoms. Something a little bigger than a small cut, as in a class II hemorrhage, would be a loss of 0.30 Liters of blood or 1.2 cups. The amount of blood loss to cause death would be more than 0.40 Liters or 1.7 cups.

The police would not confirm how much blood was found but told Trista that it was “more than a small cut would produce.” I’m not a doctor or a forensic scientist so I could not tell you what one would classify as a small cut.

For the police to use words like “troubling” and “magnitude of this investigation”, I believe that there are other factors that play into the blood evidence. Maybe it is that someone else’s blood was found along with Ayla’s. Maybe it’s that some was visible to the naked eye while other areas had to be illuminated with luminol, which means some of it was cleaned up.

Since it is nearly impossible to clean up every trace of blood at a crime scene, luminol is especially effective at detecting minute traces of blood that may not be visible to the naked eye.I found this article (page 4-6) that explains the finding of blood at a crime scene, how luminol is used and how they can tell it is blood instead of another substance.

When I take in account that Ayla’s blood was found both visibly and with the help of luminol, it is more than a small cut would produce, and they had the 2 DA’s come look at the home on Violette Ave., it offers me little hope that this evidence isn’t relevant to Ayla’s disappearance.

Blood is the most common, well-known and perhaps most important evidence in the world of criminal justice today.

There's no substitute for it, whether for medical or forensic purposes. Its presence always links suspect and victim to one another and the scene of violence. Bloodstain patterns tell a lot about position and movement during the crime, who struck whom first, in what manner, and how many times.

This destroys most alibi and self-defense arguments for crime, and at the very least, trips most suspects up in their explanation of what happened. Over the years, criminals have tried many ingenious ways to hide, clean up, and remove blood evidence, but it's an area where criminal justice technology has always stayed one step ahead of them.

In forensic law, blood has always been considered class evidence, but the potential exists for individualized blood typing, and even today, forensic serologists can provide testimony with some strong probability estimates linking a single individual, and that individual only, to a bloodstain. Consider that identical twins may have the same DNA profile but completely different antibody profiles, and you begin to see how promising the field of forensic serology really is. Forensic Serology

18 comments:

  1. No one describes blood volume in terms of "ounces" or "cups".

    Lay people define BV in "pints" (why? I'm not sure, but it seems to be the arbitrary unit measure of choice).

    Medical professionals term blood volume in Liters(L) or milliliters (mL).
    Occasionally, I've seen BV represented in cubic centimeters (cc).

    Ounces??
    CUPS??
    Those are your usual volumetrics of choice in *cooking recipes*.

    I could see a lay person (one who ONLY understands reference volumes related to their experience with cooking in their KITCHEN) needing to convert BACK to units of cups or ozs., when given a blood volume expressed in mL by a professional, in order to get a "visual" for what that amount would "really" represent.
    Just a thought.

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    1. What's your point other than trying to be a know it all ?

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  2. You are right! I did use Liters first but I love to cook so it is easier for me to visualize a cup than it is to visualize a Liter, so I figured it would be easier for some people also.

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  3. I guess we have to assume the blood found was probably Class ll or lll, for it to be disturbing and more than a small cut would produce, yet not enough, alone, to prove her death. JMO

    Also I don't know where the "2 cup" rumor came from, but I can't even take that into consideration without a source.

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    1. = 473mL = 1 pint of blood.

      The average toddler of Ayla's age and estimated weight range could be expected to have a total blood volume of 918 to 1017mL (around 2 pints).

      So, according to the figure of 16ozs of Ayla's blood having been "found", she would have lost about half her blood volume.

      Given that this was blood evidence someone tried to clean-up, I think its safe to assume they didn't leave behind a pint to be collected!!

      BUT, I believe that IF there was stain impression left (one representing a former "pool" of blood) that had distinct, "un-smeared" borders it MIGHT be possible for investigators to have ESTIMATED the approx. amount of blood that the stain represented. (circumference/diameter/surface area)
      *******************************************

      ITA, Kit!

      I find it *plausible* that this information MAY have been given to a DiP during interview as an estimate, and somehow ended up being heard second or third-hand, and finally been posted on a blog.

      However, even if this IS the case, the information could have been altered in the rumor repitition process, AND without having a source to attribute it TO, there is simply NO WAY of judging the potential validity.

      The units of measure suggest to me that the source of the rumor, as posted on the blogs, came from a lay-person rather than a cited LE source.

      It is definitely not a pro-DiP leak, though, because it certainly does NOT serve to deflect guilt or suspicion.

      In the past, Trista has freely repeated info that LE has told her directly, acknowledging she is under no constraint from doing so, although LE will likely not make a public confirmation.

      So...I don't think the leak came from Trista.

      The figure COULD be posted by a random troll who enjoys making waves on blogs for kicks.

      BUT, if the rumor IS based in fact..who MIGHT be the source??
      Derek Tudelas sister, perhaps?
      She WAS notably absent from the MS interview where Derek, Mom and Dad all rallied around JDiP.
      :/

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  4. Why would you use cups to describe the loss of blood? It's pure speculation to say how many "cups" are there. It cannot be scooped up and measured. wtf

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    1. I'm sure professionals are aware of that and know what they are talking about.

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  5. Rumors do sometimes stem from truth, so I guess we'll have to wait and see on this one.
    If LE told ME they found a certain ml of blood, thats how I would relay the info to others, or maybe the amount in ml AND a conversion.

    At the same time, VTLady and T4A, I appreciate the amounts converted to cups/ounces because it does make the visual easier.
    I'm kind of being hypocritical, I guess...

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    1. Or you're just being dumb. That doesn't make sense, if you can't visualize cups/liters/pints, go back to kindergarten.

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    2. No, you're not being hypocritical in the least!

      It's just handy to realize that since this rumor was reported to us by an "Anon", in units of measure described as "ounces"/"cups", that the one who posted the rumor, or the one he/she HEARD it from DIRECTLY, is someone who had converted the units to familiar household equivalents, in an effort to make the blood volume identifiable.

      We can assume that this leak (if based in truth) is not coming from someone with a medical background or an LE source directly!

      I also think that if a RANDOM TROLL was behind this rumor, they would have looked up info on blood loss/volume on the internet, and reported the information in terms of "pints of blood" which is the arbitrary, standard used in medical info articles designed to be READ by the lay-person.

      The units of measure used to describe, IMHO, are extremely telling as to the origins of the rumor.

      I think it's based in fact, but being relayed by someone who could NOT visualize "how much" blood was represented by the BV that LE was telling them the blood-stain is thought to have represented.

      The person took the info and converted to the units of measure they had experience with:
      CUPS and Fluid OUNCES, familiar to them from cooking recipes.

      "People will tell you who they are"

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    3. It is a rumor. Someone made a comment on the Find Ayla Reynolds FB page about blood amounts but it wasn't real, it was sarcastic. Someone ran with the rumor and questioned it as being real in the posting. The rumor can be found under the 2nd posting.

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    4. I highly doubt that someone randomly addressed Ayla's blood loss on FB by just throwing that info in a posting.

      That makes no sense.

      It came from somewhere, whether it's a legitimate fact yet or not.

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  6. Thanks for the suggestion anon. I'll see if I can enroll in the fall. Or maybe HT is accepting new "students", seeing how she is running her business into the ground.

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    1. I would join you but I'm a wee bit afraid of HT !! :-)

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  7. Pat Brown the profiler, says ONE CUP of blood in one of Levi's radio shows. It shocked me to hear that and I wondered where she came up with that figure. I don't know if she is full of BS like Pete or if she knows what she is talking about.
    She said it 'off the cuff'; I'm not trying to pin her down (listen for yourself) but yes, I was surprised when she 'blurted' ONE CUP!
    I have heard that her rep is in the shitter from the McCAnn debacle, but hey, this aint TMZ for Court TV.
    I am more inclined to believe the ball point pen circles at this point, but hey..don't let me sway you..make up your own fkin mind kookie nuts.
    Very good blog J4A!

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    1. Thanks, I cant take credit for this article though, Truth4Ayla wrote it and is wonderful! We both work really hard trying to get Truth and Justice for Ayla.

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  8. T4A: I have struggled with this blood evidence as well. The thing is, how soon would they have known in the investigation that the blood was Ayla's? I think of a small cut as being one that is superficial in terms of depth and small in length (let's say <1.5cm), but even a small laceration on the scalp can produce a lot of blood due to it's vascular supply. HT mentioned that there were 3-4 drops of blood that were circled the size of a pen tip (perhaps this is why she thinks the blood evidence doesn't mean anything, dismissing that blood was also seen with luminol). I suppose that could mean that they were several mm in diameter--could they be the result of a splash from a larger drop (which could be from an innocent injury) or was it splatter from a high velocity injury? So I have to conclude that if MSP said it was "troubling" that their blood splatter analysis didn't show an innocent pattern, IMHO.

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