By James Zambroski
January 19th, Day 9
Four Dots Of Blood = Life In Prison?
Since David Ray Camm's fate could hinge on four drops of blood each the size of a pencil point, it might be worth a layman's tutorial on this whole business of high velocity blood spatter.
We can do this two ways: you can Google the term and come up with 126 hits (42 on Yahoo, including several news stories) or you and I can talk about it now.
You probably know a little here and there on the subject, but I won't assume, nor will I be too condescending in the lesson. Let's have a little fun. After all, it's not our life on the line.
There is a CSI aura about this whole notion; there is some science to it as well, allegedly.
The first thing we have to understand is how fast does a bullet travel? Since the Camms were murdered with a .380 caliber weapon (which has never been recovered, by the way, but we do have the shell casings, the thing that is basically like the discarded stage of a rocket), we know the round that hit each of them was traveling at about 600 feet per second (Petzal, David E. "How fast is a speeding bullet" Field and Stream. 97 (1992):23).
Okay, that's the last footnote of attribution I'm going to use in this column (today); the rest you'll have to rely on what I know from life, experience, a few remaining brain cells and what about a half-dozen lawyers connected to this case have taught me over the years.
And by the way, even though I do have a bachelor's degree in English from the University of Pittsburgh, I'm not ready to hire myself out at $200+ per hour on the subject; I might make an innocent mistake or two here and there (now I'm covered), but I do know more than someone considered dangerous with just a little information.
The speed of a bullet is accomplished when a piece of lead (roughly the size of the first part of your little finger, depending on the bullet's caliber -- size) is blasted out of a hollow brass shell casing that's filled with gunpowder.
When the 'hammer' on a weapon -- that spring loaded thing that cocks back and has a point on the end of it -- hits the center of the back of the casing (when one pulls the trigger, releasing the hammer), the powder burns rapidly, creating gas that fires the lead projectile out of the barrel and toward it's intended target (in this case, Bradley, Jill and Kimberly Camm).
There is enormous amounts of energy and speed carried by this piece of lead. When the projectile hits an obstacle, it rapidly slows down and that energy and speed is transferred to whatever it strikes. When it's a human being, the energy destroys surrounding tissue, which is often fatal, depending on where it hits.
When the target is part of the human body, blood and tissue are blown back toward the point of origin of the shot. It's the damndest thing; you'd expect the material to be propelled forward, but that's just not the case; I can't say exactly why because I'm not a physicist; you're just going to have to trust me on this one.
Blowback occurs when any target is struck, but when that target is human, naturally, blood and tissue, the stuff surrounding the bullet's entry point, is what's blown back toward where the fired round came from.
For those of you old enough, the historic example of this you might remember was during the assassination of President John F. Kennedy. If you've seen stills from the Zapruder video of that killing, you remember that Lee Harvey Oswald fired the fatal shot from behind and above the presidential motorcade.
The President was hit in the back of the head; each slow motion, frame by frame viewing of Abraham Zapruder's accidental documentation of history clearly shows the back of the President's head coming off back toward where Oswald fired.
In the frame or two before Kennedy's head begins to disintegrate, you see in the sunlight a yellowish halo surrounding it. That is high velocity blood spatter. A mist of gore traveling at a high rate of speed, backwards.
If Oswald had shot Kennedy while standing in the backseat of the president's limousine, he'd have been covered with that mist. He would have been hit by high velocity blood spatter.
The prosecution experts say that's what happened when David Camm fired a bullet into his daughter, Jill's, head. His shirt was struck by high velocity blood spatter; four dots of it.
Camm, of course, says Jill's blood wound up on his shirt when he reached into the Bronco to help his son, Bradley. He says his shirt came in contact with Jill's blood and that's how those dots wound up on the front of it.
Now we know where high velocity spatter comes from; next we have to understand its properties.
The energy in a fired projectile is focused by the barrel. The gas that drives it is kept within the confines of the barrel. But in the energy transfer, there is nothing restricting the blowback to such a confined space. The blood begins traveling through the air, and as it does, it spreads out over an area and begins to form tiny balls about one millimeter in diameter -- about the size on the end of a lead pencil (25.4 millimeters equals an inch).
Robert Stites and Rod Englert, the prosecution's experts, say the farther the blood travels, the smaller the spheres become and the quicker it dries. If it's too dry or too small, it won't stick to whatever it strikes. Therefore, they calculate that Camm had to be four feet or less from Jill when he was struck by the high velocity impact spatter.
So what's the difference, you ask, between high velocity blood spatter and blood that is transferred to a fabric (like a t-shirt) from contact?
Now it REALLY gets interesting (ahh, yeah).
The prosecution's experts will say that because those tiny balls of blood dry so quickly, they don't have time to flow into the fibers and threads of the fabric, they actually surround each fiber, but don't get soaked in.
Blood stains made from contact, on the other hand, have more time to soak into and through each fiber. They say the difference is so striking upon close examination that one can instantly tell whether it's contact of high velocity spatter by merely examining a stain close up.
So this case is likely to boil down to microscopic examination of individual fibers in Camm's shirt. This thing will make hanging chads on Florida ballots look like child's play.
Are you getting all this? Congratulations. You now qualify to be an honorary member of the David Ray Camm jury.
But don't forget. If you goof this up on four pinpoint drops of blood, Camm goes to jail for the rest of his life. Welcome to the American judicial system.