Behind The Tape
Wednesday, December 23 2009
Grrreetings Class! Today we will talk about rigor mortis. It's the reason bodies are often referred to as "stiffs!" Since this is Kindergarten Crime Scene, we won't go into all the chemical reasons behind why the body turns stiff after death. In a nutshell, when your body stops breathing, your cells no longer receive oxygen. Without oxygen, the cells get a build-up of calcium ions, causing the muscles to stiffen. This continues until the muscle proteins start to break down during decomposition.
Even that explanantion is a bit complicated. Sooo . . . . to make it even simpler. When you die, you stop breathing and start to stiffen up. This stiffening is gradual. It takes a while. The stiffening isn't permanent either. There are a LOT of factors which affect rigor mortis, but in general, we say 12 hours in, 12 hours out. (And now that I've told you that, I'll tell you why it isn't true!)
Temperature affects it. You stiffen faster and go out of rigor faster in warmer temperatures. Cold temperatures slow it down. Physical exertion prior to death speeds it up. If you were jogging and dropped dead, you'd stiffen up a lot faster. It also happens faster in folks with low muscle mass, like old people or children. It happens more slowly in fat people. There are MANY factors to consider when using rigor mortis to determine how long a body has been dead.
There's also a pattern to the process of rigor mortis. The stiffening tends to take place in the smaller muscles in the upper part of the body first, and then travel down the body. That means the face and head. It becomes noticable first in the eyes, mouth, and jaw. (This is why they used to put coins in the eyes of the deceased to keep them closed!) The process proceeds for 12 to 18 hours until the body is literally "stiff as a board." Then it gradually goes away. The muscle proteins break down and the body loosens up again.
Now, how does that affect my job?
Like post mortem lividity, rigor mortis is a good way of telling me if my body has been moved. Rigor mortis DOES give you a pretty accurate picture of the POSITION of the body when it stiffened up. If I come in the room, and Grandpa is lying on his back with his arms in the air, I'm gonna assume that someone moved Grandpa. If Grandpa is stiff as a board, and you tell me he was watching Oprah in the recliner just two hours ago, it's gonna raise my eyebrows a little.
When considering the factors that affect it, rigor mortis still gives a "rough" time of death (really rough). Although I don't put a lot of emphasis on it, rigor mortis is still something to consider when you look at a crime scene.
Rigor is definitely something to consider when you have to bury large farm animals like horses or cows because it determines how big the hole has to be. I've heard horror stories about friends having to break legs (it makes me shudder inside). It grosses me out and I won't go into detail. I'm sure you get the picture. Because I know that rigor mortis is a natural state of decomposition, I accept that I will have to deal with this when putting down large farm animals. Because there is often a delay between the time you must put them down and the time you can get a backhoe out to the farm, things are a lot easier for everyone if you don't try to fight biology. Use some hay string to tie legs in a fetal position when the body is still flexible (just until you get them in the hole). To some folks it doesn't matter, but to me, an old horse is an old friend, and I will treat accordingly.
Okay, enough of that! To conclude, like post mortem lividity (also called livor mortis!), rigor mortis is a natural state of decomposition and a useful tool at crime scenes.
Sunday, December 20 2009
Today we will talk about hangings. (Please forgive for the sick Christmas humor! That was pretty bad.) This is really Yuck stuff anyway though, and a great deal of humor is required if one is to get through it. With that said, let's forge ahead!
When I'm called to a hanging my first question will be, "Is this a suicide?"
Most hangings ARE suicides. My job is to look at the body and determine if my dead guy, (let's call him "Fred" today!) really committed suicide or if someone murdered Fred and staged it to LOOK like a suicide.
So let's say I walk into the room, and there's Fred, hanging by the chimney with care. (Excuse me again!) Fred is suspended from the balcony railing by a rope. Okie Dokie. The very first thing I look at is how the rope is wrapped around his neck. Most true hangings produce a classic V-shaped pattern in the neck. There will be a void where the rope doesn't have contact with the neck and everything else will have a groove where the rope dug into Fred's neck.
I will not be concerned too much at first if I see that Fred's hands are tied. Believe it or not, some people go to great lengths to keep themselves from "saving themselves" if they decide, "Crap! This hurts! I change my mind!"
If Fred is hanging beside a stool, he probably just stepped off the stool, rather than doing a swan dive off the balcony. While it doesn't rule out murder, it is something to look for. I'm also gonna examine the balcony. Does it look like a struggle took place? Does it look like Fred willingly Peter Pan'd or did he have help getting over that railing?
Did Fred have health problems or a history of suicide attempts in the past? Contrary to the popular myth that people who talk about suicide don't actually COMMIT suicide, most people who kill themselves have talked about it and have tried several times in the past. In addition to the physical evidence, it's also nice to know that Fred was having an affair with his secretary and her husband is a 6'5" hulk who has recently stopped attending his Anger Management Classes.
What's another thing I'm going to look for, Class? You there! You in the back! Answer the question! What is another thing (that we've talked about) that I will be looking for?
YES! We will look at Fred's post mortem lividity pattern! Where did his blood settle when he died?
When we take Fred down, we'll be very careful to secure the rope, careful not to disturb the way it's wrapped or tied around his neck. Once Fred is lying beside the Christmas tree, we'll start looking a bit closer at his lividity pattern. Let's say the room initially looked like Fred tied a rope around the railing, put a stool under it, stepped on the stool, tied the rope around his neck, and then tied his hands with the rest of the rope, before he stepped off the stool. If this is the case, what should Fred's lividity pattern look like?
You there! Sleeping in the back! Yes, you!
CORRECT! Fred should have pooled blood in his legs! (and maybe an eggplant face)
We lift Fred's clothing and guess what! Fred's blood is pooled and fixed along his back. There is no classic V-shaped groove around Fred's neck where the rope is tied. Hmmmmmmmmmmmmmmm . . . . Fred just got a lot more interesting.
Now would be a good time to check out the secretary's husband who has booked a flight to Barbados for Christmas.
Wednesday, December 16 2009
Grrreetings, class! Today we will talk about insect activity on a body. Say it together, class, "Ewwwwwwwwwwwww!"
Depending upon your climate, insect activity (that's a nice way of saying "maggot infestation") on your body can happen pretty quickly. I won't go into the kinds of bugs that appear first and all that--this is a Kindergarten Crime Scene Class. Again, I'm not trying to be condescending, I really THINK in those terms. Most of us are not Forensic Entomologists. When a scene calls for that kind of scientist, we can certainly call one in for assistance. (I just love bug people!)
Maggots are really the larval stage of flies. They are not the only insect to show up on a body. For our purposes though, they're the insects we'll focus on for today.
So where was I? OH! We were talking about insect activity in bodies! The point I want to stress for this lesson is that insects (maggots) tend to gather around openings in the body, i.e., the nose, ears, eyes, mouth and genitals. This is a given. So . . . when you see a body that has insect activity in the chest cavity, there's a good bet that there is a HOLE in the chest caviity where the little boogers got started. Class, what causes holes in the chest? RIGHT! Bullets and knives! (and hammers, hatchets, machetes, shotgun pellets, and so on, but you get the point.) If you see a body with lots of insect activity in places where they really shouldn't have it yet, you need to look a little closer. The death that on the surface looks like a natural, could be a murder!
And our quote for the day comes from Clifton Fadiman:
"The biochemist J.B.S. Haldane was engaged in discussion with an eminent theologian, "What inference," asked the latter, "might one draw about the nature of God from a study of his works?" Haldane replied, "An inordinate fondness for beetles."
Monday, December 14 2009
Say it fast! Post mortem lividity! Has a certain ring to it, doesn't it? Nah, not really. But, it is the bread-and-butter to much of what I do. In kindergarten terms, (and I don't say this to be condescending, I just happen to THINK in kindergarten terms!) post mortem lividity means "where your blood settles when you die" (and for those of you who live in Inner-City Anywhere, the answer is not "on the sidewalk").
Back to our lesson . . .
When you die, your heart stops pumping blood, so blood stops moving around your body. Slowly, it begins to settle to the lowest parts. So if you die laying face-up in your bed, your blood will settle in your back, the back of your arms, the back of your legs, etc. If you hang yourself, the blood will settle in your feet (except for the blood that's trapped in your head by the rope you're hanging from). Then you can end up with an eggplant-colored face. (I know . . . say it together, class, "Ewwwwwwwwwwwwwww!")
Since this is kindergarten, there are only two things we need to know: lividity pattern and whether the pattern is "fixed."
When blood settles to the bottom, it stays there. After it's there for a long time, the pattern becomes "fixed," i.e., when you press your finger into the skin, the skin doesn't blanch much. Try this on your hand right now . . . push your finger deep into the skin. The skin will blanch (turn white) as the blood moves away from the pressure. If the lividity pattern is fixed or close to fixed, the blood won't want to move, so the skin won't blanch much. Whether or not the pattern is fixed helps us to determine how long you've been dead.
Another thing that's important about lividity patterns is "blanching pattern," because although the blood will settle to the lowest part of the body, it often doesn't settle at points of contact with hard objects. For instance, if you are lying on your back, there will often be light spots where there is very little blood, such as on your butt cheeks or shoulder blades.
A fixed lividity pattern is a wonderful way for a quick check on whether or not your body has been moved. For instance, let's say you died face-down in bed. The blood will settle where? Yes! In your tummy and the fronts of your legs and arms and your face! Again, we're talking about the possibility of an eggplant-face here. I know . . . get it out of your system. "Ewwwwwwwwwww!"
And let's say, you're lying there, (minding your own business) when someone finds you. They freak out. (People do that when they find dead people.) Then they call 911. Now you've been lying there, dead, for a while. You've got an eggplant-face, but the 911 dispatcher will often still tell the person to put you on a hard surface, (i.e., the floor) and turn you face-up to do CPR. (Important note: CPR doesn't work on people who have been dead so long they have an eggplant-face.)
Eventually, I end up there (it's my JOB) and I see that you have an eggplant-face, and it looks like you have a horrendous sunburn or bruising on the front of your body with white spots on your knees. I KNOW you have been turned over. Depending on the situation, this may, or may not be a problem. Sometimes people move a body for completely innocent reasons, they cut down folks who are hanging, or they try CPR on folks who are already long-dead. Other times, folks move a body to change or conceal a crime scene. Part of my job is to figure out IF a body had been moved, and if so, why.
And that . . . is your Forensic Lesson of the Day! (Clear as mud, right?) I wanted to provide photographs, but obviously I couldn't use pictures from my own files, and wonder of wonders, the internet wasn't filled with tasteful photos of post mortem lividity patterns (now that's an oxymoron if I've ever heard one! There is no such thing as a "tasteful lividity pattern" photograph!) Anyway . . . here is Professor Puppy to teach Kindergarten Crime Scene!