Free Blood Secrets: Chronicles of a Crime Scene Reconstructionist by Ann Rule Page A

blood.
    Every month, the mobile slaughter van would arrive to kill four or five fattened steer. The man who ran the operation shot them in the head before butchering them, a sight that would have turned some folks into vegetarians on the spot. But having grown up on a farm, I had long ago grasped the link between slaughter and supper. I had conquered any squeamish urges as a little kid watching Ernest Braden, a neighboring farmer who did his own butchering back in Wall, slide a coffee cup under the slit he had cut in a steer’s throat to catch the blood—and then drink it. Besides, all that cattle blood provided ideal research material for a homicide detective.
    Before mopping up the barn, I would study the blood patterns made by the gunshots and the bodies, then I would refrigerate bottles of blood to help me re-create details from cases I was working. Conducting my own experiments using cattle blood often helped me to more effectively unravel puzzling clues in murders I was investigatingthan I could have done on a crime scene where other people are always tromping around trying to do their jobs, where time can be limited, and where evidence is already cold.
    Whenever I had spare time, I would gather up a notebook, a camera, a bottle of cows’ blood, and anticoagulant from the barn to further my study of blood patterns. I dribbled blood from my fingertips, from the points of knives, and from holes in plastic garbage bags dragged across the barn floor. I tried the same tests on cement, gravel, dirt, sand, grass, wood, and carpet to find out how the trails of blood differed. Then I did the experiments on ice and snow and watched what happened when it began to melt. I made notes about how the droplets got absorbed or distorted depending on how porous or soft a surface they hit.
    In those days, just over half of all the homicides in Oregon were committed with guns, so I spent a lot of time shooting into blood with .22s, .38s, shotguns, and automatic weapons, and studying the fine red mist the impact created. I found out that the more powerful the gun was, the finer the bloody mist it generated. It’s common knowledge among blood experts now, but back then it wasn’t.
    Fortunately, the barn was massive—ninety feet long, thirty feet high, and forty feet wide—large enough to convert to a horseback-riding arena (which is what the people who later bought it from us did). That meant there was plenty of room to experiment without endangering the animals. If I was doing a test that might make bullets ricochet, I stacked phone books or set up plywood around my work area as a protective backdrop. Living in the country—where deer, duck, and pheasant hunting was common—helped, too, because nobody panicked at the sound of a gunshot. I could fire all day long without raising an eyebrow.
    Gunshots were just one part of my research. I also hit puddles of blood with bats, hammers, boards, and other blunt objects at differentangles, rates of speed, and degrees of force. They generate a coarser mist with larger droplets than guns do—a pattern now classified as “medium-velocity spatter.” I also scrutinized the cast-off that various weapons made on wood, metal, fabric, glass, and other surfaces. “Cast-off” is the term crime scene reconstructionists use to describe the blood that flies off a weapon as it’s wielded repeatedly.
    During the tests, I wore different types of clothes to find out how much blood soaks into certain fabrics and where it concentrates based on the type of attack—swinging a baseball bat, raising one for an overhead blow, and so on. One surprising observation I made was that during a beating, very little blood travels backward onto the attacker—the impact projects most of it forward onto walls, furnishings, and whatever else is in front of both attacker and victim. It’s vitally important for homicide detectives, prosecutors, defense attorneys, and jurors to understand this concept, but plenty of them