PathologyTranscriber: Ben Contratto
Dr. DavisPage 1 of 9
07 Nov 2006Forensic Pathology
1)This is a house in Wales where I stopped to ask for directions once. They told me how to get where I was going. When I was leaving, I thought it was pretty, so I took a picture… and where I was going was pretty too, but when I got the photographs back, I realized that where I was going wasn’t any prettier than where I was right here. So I just wanted to show that to you as students.
2)Forensic Pathology – this is what I do
a)I identify remains and figure out the cause of death and manner of death
b)Causes of death: whatever it is that set a person on the course of being dead.
i)They could be shot. They could overdose. They could have a myocardial infarction from coronary artery atherosclerosis. Pneumonia is also a cause of death.
ii)Sepsis is not a cause of death; it’s a mechanism of death. You need to know what the organism is and where the infection it is. It’s not enough to just say that it’s floating around in your blood. So you could die of sepsis from endocarditis, but not from sepsis alone.
c)Manner of death: this is either natural or unnatural death
i)So this could be accidents, homicides, suicides, etc
3)The Autopsy
a)It’s a medical examination performed on someone who happens to be dead.
b)I’m a physician, so we start with a history (just like any type of medical examination).
i)We can’t ask the patient how they’re doing and what they’re there for, but we can give a history by finding out something about the circumstances of which the body was found
(1)If the body is found in an alley in a pool of blood, that’s one kind of history.
(2)If it’s found in an alley NOT in a pool of blood, that’s another history
(3)If the person is 73 years old, didn’t wake up the next morning… that’s even another type.
c)Gross examination
i)External
(1)We look at the outside head to toe for any injuries that might be there. But we’re not always looking for murder; we just want to know why people die. If they have a scar or pneumonia, we have to find that out.
ii)Internal
(1)We don’t care so much about the soleus muscle. But we’ll look at the organs by making an incision from shoulder to shoulder and then all the way down and reflect the skin back. We see the heart, lungs, liver, kidneys, etc.
(2)Then we also look at the brain by making an incision from ear to ear, reflect the skin back and use a saw to cut around the top of the calvarium. We put a notch in it like you would on a jack-o-lantern so we can put it back on the same way it came on easily.
(a)We try to do good work and we have a great interest in giving the family the ability to have (if they wish) an open casket funeral when we’re done. So we’ll remove and cut through all the organs, and then save a bit of everything just in case – but all that we save is about the size of a fist. The rest goes back in and gets buried.
(b)Most of the body gets covered by clothes, so that’s not a problem. And most people still have their hair, so the funeral directors will comb that as best they can to cover stuff up. If a person is completely bald, we cut as far back as we can, but you can’t hide that incision if they’re completely bald. You’ll notice the pillow in the casket is kind of a bowl shape, so that helps too.
d)We also look at microscope slides and toxicology reports.
i)About 30-40 percent of the cases that come through the coroner’s office involve alcohol or drug abuse.
e)Then I complete the death certificate and the autopsy report.
f)Special requirements: I’ll talk to the family if need be. I’ll go into court to testify.
4)Identification of Remains
a)First question is “are they human?”
i)The police came to me with a bone that someone’s dog pulled up in the backyard. It was a portion of femur with a very large head… it was very large and looked like a cow, so it wasn’t human and we threw it away.
ii)If they are human, we have to try to figure out who the person is. 90% of the time, the medical history is going to tell you the answers you’re looking for. I can’t get a proper history if I don’t know who the person is in the first place.
(1)If we don’t know who it is… just a random person found dead in a field or in a car, then we have to look for clues:
b)Clues and scientific identification
5)Tattoo
a)Here’s an example of a clue. This is a unique tattoo I saw. It says “Death before Employment”. Doesn’t it tell you something about that guy? They can’t talk to me, but I get my history.
6)Tattoo – Grateful Dead bears
a)Not everyone has a tattoo like this, but if I do see a tattoo like this, what kind of cause of death becomes more likely? And that’s what it was.
7)Fingerprints
a)I don’t mean to demean the importance of clues, because a clue can get me on the right track, but I’d rather try to find out a positive ID scientifically. Fingerprints are an excellent way to do that.
b)Most of the people that I get die under nefarious circumstances and are people who have had run-ins with the police before. So if their fingerprints are on file, that’s easy. You can find the sets of prints that match best and then see who it is.
8)Dental x-rays
a)Maybe their fingers are gone... maybe they’ve decomposed or get burned off. So we have to go to something else…
b)dental identification is a perfectly good way to identify someone with absolute confidence. The drawback to dental identification is that there isn’t some repository of dental x-rays at the police station. This is when you need to have a clue. I have to know that it’s this guy so I can go to his dentist and get the films. I can’t search every dentist in the county much less Alabama or further.
c)Usually these are pretty easy. I could probably make this dental comparison, but in cases where it’s less clear… or if it’s a homicide and I want absolute confidence, I get Dr Weems to do it (he works with their office)
9)other x-rays
a)“pay no attention to these bullets” [funny guy]
b)This is the configuration of the frontal sinus. The frontal sinus is unique in each person, so we can use that to positively identify someone by comparing anti-mortem films and a head radiograph.
c)[Dr Waites asks a question] “It’s unusual, but they did more when Dr Martinez was establishing in the state that it was a reasonable way to do things. Now they’re more likely to just accept our say and they’re willing to let us speak to that just to streamline the process. if they wanted to be obstreperous [adj. 1: marked by unruly or aggressive noisiness; 2: stubbornly resistant to control] about it, then sure, they’d be there in a New York minute”
d)One of my points is, I don’t know what kind of prank phone calls dentists get, but I will never call your office as a prank. The first question I’m always asked when I call a dentist is “is this a joke”… and we don’t joke like that. Must be a part of Kubler-Ross’ stages of grief. [smart funny guy]
10)Picture
a)Here is an example of a case where identification was made by dental comparison. This is a bucket that used to be suspended and it held molten aluminum. The chains broke and fell into this pit where a person happened to be. Molten aluminum is pretty hot… it says so on the bucket.
11)This is all that’s left of him. I’m amazed that there was any left at all. It’s very difficult to entirely consume the body of an adult by fire.
12)These are his teeth. We had a pretty good idea of who he was, but we went through the formality and show that it was this person.
13)Occasionally, we try to make a clay model of someone… you see this on television some.
a)The actual skull is underneath the clay and there are formulas that have been developed to tell how thick the skin is in different spots. So the artist tries to build up the face and make it look like the person may have looked.
14)Profile view
a)The hair, lips, nose, and ears are a guess. Every once in a while, it’s helpful and you can get the clue that you need to proceed.
15)Violent Injuries
16)Blunt Force injuries
a)These are the foundation of forensic pathology.
b)This is an abrasion… so a scrape or a rug burn. You get this raw area.
c)This person was in a car wreck and his face hit the windshield. Of course there were worse injuries which actually claimed his life.
17)This is an abrasion where the force was tangent to the skin.
a)This guy was riding a motorcycle wearing shorts and a t-shirt. He had a wreck and slid across the pavement and got all this abrasion. He actually slid into a pole and broke his neck… so the abrasion won’t kill you, but the broken neck will.
18)This is another kind of abrasion
a)The skin enlarged for a split second as a result of a gunshot wound… so much that the neck slapped up against the necklace and you can see the holes in between caused by the links in the necklace. That’s an impact abrasion where something has crushed the epidermis and left an abrasion. So this reproduced the pattern of the object which formed the injury and that can be helpful
19)What object formed this injury? A zipper.
20)A woman was wearing this shirt when she got in a wreck and hit the steering wheel. It left that abrasion. It’s not that important in this case, but in other cases it can matter.
21)Here’s a woman who was run over by a car.
a)In older days they tried to match the tire tracks and such to try and find the car that matched. But today they send this to DNA and try to find her blood on a car.
22)This is a contusion. It’s another form of blunt force injury.
a)Something has struck the skin and the skin isn’t abraded, but the vessels deep to the skin have ruptured and blood has leaked out into the surrounding tissue. This old woman fell and hit the back of her head.
b)Notice that it has different colors. We’ve all had bruises and they change color from blood to bilirubin to biliveriden, to hemociderin, to resorbed… and people get it in their head that they can tell the age of an injury by looking at the color. But if someone saw you and you had a bruise on your arm on Monday morning and they asked where you got that bruise… you’d say “well that party Saturday night I fell and hit my arm and that’s all the detail I want to get into.” You wouldn’t look at it and say “well it’s green, that’s about 36 hours, so that was Saturday night”. So it’s history that reveals that and the color of the bruise doesn’t really tell you how long ago the bruise formed. We don’t try to give an age estimate of a bruise based on it’s color
23)Sometimes bruises are subtle.
a)There are two here. These are on a child in a suspected child abuse case. This is a big deal because we don’t want to make a mistake… Someone might try to say this is a birthmark.
i)Birthmarks are from pigment in the basal layer of the epidermis whereas a contusion is ruptured blood vessels deep to the skin.
24)So we can incise the skin and tell that it’s a bruise and not a birthmark at all.
25)Lacerations – another type of blunt force injury
a)A laceration occurs when some force is brought against the skin which is greater than the skin is able to withstand. So the skin ruptures and tears apart. It’s much like ripping a sheet of paper in two in that it occurs in whatever direction based on where the skin is weakest at that point
b)They’re different from an incisal wound in which there is a sharp edge that cuts through the skin and divides the tissues one side from another. There will be a completely clean cut in an incision. In a laceration, there are structures deep to the skin which will continue to bridge the gap because they are stronger than the skin (such as blood vessels or tendons).
c)Tissue bridging is the hallmark of a laceration.
d)Often you’ll see some abrasion b/c of the blunt object. To clarify, a blunt object is pretty much anything but a knife (which is sharp)… this includes a chair, a 2x4, a bat, a fist, the ground, etc.
26)This is an example of a laceration.
a)This is on the head of a lady who was late for work. She lived up on a hill and was backing out and ran off the edge. So she spun the tires and couldn’t get back on the driveway. So she opened the door to check her progress and punched it one more time. Well, that time it caught and the car went backward and trapped her head between the car door and a tree trunk. So I used to do the same thing, but now I don’t… and you shouldn’t either. Stay in the car while you’re spinning the wheels.
b)You can see the tissue bridging. She doesn’t have abrasion probably because her hair protected her to some extent.
27)Fractures
a)If a bone breaks you have a fracture. Not everyone who dies goes to the hospital. This guy didn’t go to the hospital… he comes straight to us. This is from a car wreck.
28)In America, people have guns. In forensic pathology, you have to understand how guns work.
a)This is a cartridge that has been disassembled.
b)the casing is on the left and it’s packed with gunpowder. the bullet is on top of the gunpowder and is held in place by the crimp in the casing.
29)this is a photograph of someone firing a gun
a)when someone fires a gun, the hammer comes down and strikes the back of the bullet. It ignites the gunpowder which burns with explosive speed. It goes from a solid to a gas. The gas occupies a much larger space than the solid and it has to go somewhere. The way guns are constructed, the gas has only one way to expand: down the barrel and out the muzzle. The gases have to push the bullet out of the way as it rushes out.
b)The important part is that the bullet isn’t the only thing that comes out. All this gas comes out too. And since the reaction isn’t that efficient, not all of the gunpowder gets turned into gas. Some of it turns into soot (like what comes up from a candle when you blow it out). Some of the powder either doesn’t burn completely or at all.
c)So there are four things which come out when you fire a gun: the gas, the soot, the bits of powder, and the bullet. These four things will travel a certain distance before either be dispersed by the atmosphere or falling to the ground.
i)The gas will be dispersed by the atmosphere within a matter of inches
ii)The soot is fine though larger than the gas, so it’ll travel further through the air before being dispersed. This is the cloud of smoke which blows away
iii)The bits of powder will travel further still b/c they’re larger than the soot.
iv)The bullet will travel the furthest of all before it falls to earth
d)the differences in the distances that these things will travel can be shown in wounds we see on the body.
30)this is what it looks like to be on the wrong end of a gun. Remember this pattern b/c you’ll see it in a moment.
31)How wounds form
a)when a bullet strikes the skin, it indents the skin for a split second. Your skin is elastic… you can move it around and a bullet can do that too as it punches it’s way through.
b)The epidermis on either side which got dragged in a bit as the bullet went in snaps back to its place and will be abraded at the very edge. So there will be a very tiny blunt force injury at the edges of a bullet entrance wound
c)In contrast, if the bullet was traveling the other way, then the epidermis would be the last thing the bullet goes through. It will part in front of the bullet and the bullet will never touch it. So an exit wound wouldn’t have any abrasions on it at all
32)This is a typical entrance wound on the cheek of a young woman who was shot.
a)You can see the hole in the center formed and abrasion at the edges where it was scraped by the edge of the bullet. It has nothing to do with the spin on the bullet b/c the bullet only touches it for a split second.
33)This is a contact entrance wound
a)This was an old man who was having heart trouble andhe put a gun up on his chest and pulled the trigger.
b)The gas has to go somewhere and the only place it can go is into his body. That causes the skin to balloon outward and slap against the muzzle of the gun so you can see the imprintof it. Up at the top is the sight, you come down and see the muzzle and on the bottom is some sort of flange or ejector rod. So we know that the gun had to be in contact with the skin and that’s the range of fire we want to see in something that we want to call a suicide.
34)This is a close range gunshot wound. It’s further away from contact.