QUOTE (devca @ Jun 22 2007, 04:32 PM)

Stefanl,
I have been following the Spector trial and as my go to
forensics expert I have a question for you.
Dr. Henry Lee, an expert for the defense, is expected to testify that blood can travel six to seven feet, making it possible for Spector to have been standing across the room when Clarkson was shot.
Can that be true? Lynne Herold, the LA sheriffs Dept. criminalist
testified 2-3 ft for the mist-like drops on the Sleeves and Lapels,
of Spectors jacket
I realize Dr Lee is being paid to testify, but would he stretch the
truth? I have admired him for many years and now am getting a bad feeling about this.
Do you have any insight as a teacher on how far blood can travel?
Thanks,
Dev

Good question, Dev, and the answer depends on the size of the drops that are being described.
The high speed impact, mist-like drops that Lynne Herold is describing do not fly nearly as far as larger sized blood droplets. If Spector has droplets of blood on him that are larger in size, they would have survived the trip through the air for the longer distance of six to seven feet. A gun shot would result in mostly mist-like drops with some larger sized droplets as well.
Wound type, directionality and angle, type of trauma responsible for producing the spatter are all factors that need to be taken into account when answering that question. And yes, Dr. Henry Lee is the go to guy for blood spatter analysis. He practically invented the concept and has written several books on the subject.
How much blood was found on Spector's clothing, how large those droplets were and where on his clothing they landed are all factors to consider. Were there only a few larger sized droplets (2-3 mm), those would carry away from a gunshot wound. Were they found on the clothing of his torso or his legs? As the blood explodes away from the body the angle of trajectory would increase in size and they would probably hit farther down the body, rather than at 90 degree angles away from the site of the wound.
Why was he hit at all? I would imagine that the largest component of the spatter would be carried away from him, assuming he's shooting across a space of six to seven feet, toward the victim. If he's getting hit by back spatter, it may be either respiratory spray (larger in size than gun shot misting and coming from a severed trachea or bronchi) or it was arterial spurt, which can travel several feet.
There is an interesting tutorial on the
IABPA website concerning blood spatter analysis that explains how to determine the position of a victim when spatter was produced. I haven't found anything that discusses exactly how far each of the different sized droplets is capable of moving through the air, although physics says the larger the drop the farther the distance because of momentum.
Linda