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Zimmerman on Trial; Forensic Pathologist Testifies for Defense

Aired July 9, 2013 - 12:00   ET


DR. VINCENT DI MAIO, FORENSIC PATHOLOGIST: It passes down certain chemicals which activate the cells. Now the axons (ph), as I said, all elongated, run from cell to cell. When the brain moves, of course, back and forth due to impacts, the axons will be stretched to a certain degree. Within limited motion, the way we are walking around and such, or even bumping your head, it's no big deal because the axons can take that. If the movement is very violent, it stretches the axons and this caused -- causes injury to the lul (ph). If the movement, which is more violent, is relatively mild, the injury is repaired by the axon and there's no problem.

And then if there's a gradual increase in force, until you get something like an automobile accident where, you know, you run into something and your head goes forward and hits the panel (INAUDIBLE), that force is so great that it will injury these axons and they will not be able to be repaired. And they die.

Now, luckily, you have a lot of brain cells and a lot of connections, so you can lose a good number of brain cells and still be all right. But at some point you'll have impairment and at some point you're going to die. So impacts of the head, with this hard surface like concrete let's say, what you worry about is the intracranial bleeding and some axonal injury. More likely intracranial bleeding than axonal injury, to be honest. And so it's always dangerous.

The thing is, it's like, if you hit your head here on the floor, it's carpet. It absorbs. Concrete doesn't yield. When your head hits concrete, your head heals, not the concrete. So it's dangerous.

Could you kill somebody? Sure if you banged them hard enough. But its -- if you don't -- but even if you don't do enough to injure the brain significantly, you're going to have some stunning effect. That's what concussion -- you know these football players who get the concussion, what it is, is its axonal injury. And, you know, some can take it, some can't. Sometimes there's (INAUDIBLE) down the line. But you can get a very mild concussion just banging it -- not just banging your head on a cabinet. That doesn't do it. But, I mean, you know, you fall and you hit your head and you can get a mild concussion, a concussion. You don't lose consciousness, you just appear stunned.

I know this is not a medial term, but it's like stunning goes to concussion goes to getting worse. I think the best thing is stunned where you may not have any significant visible injury to the brain, but you are stunned just from the impact. Stunning is a good term. It's better than concussion. DON WEST, ZIMMERMAN'S DEFENSE ATTORNEY: You're suggesting it's a progression depending on how hard the impact is and perhaps how susceptible the person is to it?

DI MAIO: Yes, and how many times, you know, it is and how much force is used. And -- but at least you're going to -- if you -- if you get your head hit something unyielding, like concrete, with sufficient force to tear its scalp, you're going to be at a minimal stunned. And then it could be much worse than that. But you're going to be stunned. Because the thing is, if we all hit our heads all the time and how often do you get a scalp laceration? It's not that common. Even in people who have their hair cropped or, like a lot of people in this courtroom, are bald, you know, that removes a little of the cushion. But, you know, the thing is, is when you have lacerations, you know, there's some trauma.

WEST: Dr. Di Maio, you were talking specifically about lacerations to the scalp. I know that you've received the photographs and reviewed the evidence that George Zimmerman had two lacerations to the back of his head. If I might have the lights for a moment, your honor, I'd like to show state's exhibit 76. This has been identified as the photograph -- is there maybe another button to push?


WEST: I'll hold it up for you, in the meantime. This has been identified as State's 76, the very first photo taken of George Zimmerman that night by Jonathan Minala (ph). You've seen this before?

DI MAIO: Yes, sir.

WEST: Does this evidence some bleeding to the back of the head?

DI MAIO: Yes, sir. There's two sites of bleeding you can see.

WEST: Two -- two wound sites, if you will?

DI MAIO: Where you're bleeding.

WEST: Right.

DI MAIO: A laceration. It's a tear in the skin.

WEST: I'll stick that here on the projector just as a frame of reference. OK, That's the first picture. And then you later saw pictures where some of the blood had been wiped away?

DI MAIO: Right.

WEST: Let's take a look for a moment at 74 and how well that can be seen. Maybe not so great. What do you see in this picture in terms of evidence of injury?

DI MAIO: It looks like you've got a bruise on the left side. It's not really a very good photograph. WEST: Let me see if I can find one that may be a little bit better. These are all in evidence so the jury can review them at their leisure, but they aren't in sequential order, so I'm struggling here a bit. Let me see if I can't find it easily. If not, we will -- we will move on. No, I think we're stuck with this one for the moment. Do you see in this photograph what looks like two separate areas of swelling?

DI MAIO: Yes, if you look in the -- you can see there's an injury at, let's see, if you look at the head say at the --

WEST: I have a pointer if that would help?


WEST: May I approach the witness, your honor?

NELSON: Yes, you may.

WEST: It's the top button.

DI MAIO: There's an injury here and here which are -- probably represent the lacerations since it looks like clotted blood. But if you look right in between this kind of a valley, and the reason is, is that this impact site is swollen. And this is swollen here. So this is not swollen. So you know that there are two separate impacts. One impact here, one impact here, producing two separate lacerations with an area in between that is not swollen. And the swollen is, you know, just a bleeding under the scalp. That's what it is.

WEST: The knot or the lump that people get after hitting their head on something hard is blood as opposed to some other fluid?

DI MAIO: It's blood, right. It's a --

WEST: Talk for a moment, if you will --

DI MAIO: The medical term is hematoma, but knot is, I guess, non- medical and acceptable.

WEST: Talk for a moment, Dr. Di Maio, if you would, about the curvature of the head and why you're confident that's two separate impacts as opposed to one impact that could have caused all of the injuries that you see?

DI MAIO: Well, OK. It's real simple. It's -- you've got an unyielding surface. So when a circular area hit it, it's going to flatten at the point of contact and it's not going to flatten three inches on the other side. You have to move it over. And on top of that you can see, if it was one impact, it would be swollen between the two. But here you've got two areas of swelling, so they're separate.

WEST: You commented earlier that it's not that easy to get a laceration from impacting on a flat, solid object.

DI MAIO: Yes, because it takes sufficient force. I mean everyone bangs their head and has fallen and hit their head and you don't get lacerations, you know.

WEST: What's the mechanism by which the laceration occurs where the skin is split in some way?

DI MAIO: There's two ways you can get a laceration. One is if it's a direct, perpendicular impact. You just crush the skin. And as you crush it, you push it side -- away from the point of impact and you get a tear. The other is, if you hit it at an angle such that you bang it and slide, the concrete or -- not concrete, the surface holds it, pulls from an edge (ph) and the rest of the moving head pulls against that and so you tear. A laceration is nothing but a tear.

WEST: Here is the picture I was looking for. Let me substitute this. This is exhibit 57. And see if there's anything else here that more clearly shows what you were talking about.

DI MAIO: Yes. Again, when I was (INAUDIBLE). You can see that there's a swelling here and there's like a little valley here. And it's swollen here and then its swollen here and there's a laceration here. And this is a blood clot over a laceration. One of the lacerations is almost an inch and the other one was like a fifth of an inch. But the wounds aren't beat (ph) up when they took the photograph, so you can't say which is which.

WEST: Is the laceration itself a significant injury?

DI MAIO: In this case -- well, just that it marks -- it's a marker of force. It varies if you get a real bad laceration, rarely, rarely -- I've seen it maybe twice, people have actually bled to death from lacerations of the scalp, but not like this type of laceration.

WEST: When you say it's a marker of force, are you saying that it represents something other than just the actual injury itself?

DI MAIO: Right. It indicates that you've had severe force because your -- you know, it's not like you just bump your head or something like that.

WEST: Would it be possible to have your head struck on something hard enough to ring the bell or stun you that wouldn't actually leave a mark visible some hours later on the outside of the scalp?

DI MAIO: Oh, sure. You see there's a lot in abused children and there's not a mark on their head and then you get inside, they've even got skull fractures. So you can -- you can get severe trauma to the head without external injury, actually.

WEST: If I --

DI MAIO: That's why they're always doing CT scans, you know, when you have head trauma.

WEST: So it would be the presence of the injury on the outside, are you saying doesn't necessarily mean there wasn't additional impact or that the impact itself was minor? DI MAIO: OK. The -- what I'm saying is, is that you can get severe head trauma but actually without any marks on the head, or you can get marks, lacerations and contusions and have head trauma. They're not necessarily -- you know, more commonly when you get severe head trauma, you have some injury to the scalp, but you can get severe head trauma without a mark on the scalp too.

WEST: Sort of gauging the amount of force necessary to cause those injuries alone, would that be enough force, in your opinion, to cause this stunning effect that you talked about?

DI MAIO: Oh, yes. Anyone who's ever had a real bang on their head knows that you don't have to have a laceration or a big bruise to be -- you know it's a transient (ph) type of thing. Maybe five, 10 seconds, you know, you're kind of stunned. That's probably -- that's a good term to use. It -- medically the doctors would refer to it as a ultra-mild contusion -- concussion, but stunning would be better a better thing because people experience that, you know, when they hit their heads and they understand that and it's not really of that much significance neurologically.

WEST: If you sustained a stunning blow, like this, and then you continued to receive additional blows to the head, would the additional blows continue to cause this stunning effect?

DI MAIO: Oh, yes. Yes.

WEST: So it may compounds in a way?

DI MAIO: Yes. Actually, if you get a concussion, even if it's mild and then you within a short period of time get multiple other concussions, people have died. That's the, you know, Friday night football where they get one week and they get another one the next week, and they'll collapse and die. It's a recognized syndrome.

WEST: So in other words, these impacts could be cumulative just that night into multiple stunning effects, ultimately leading to a concussion?

DI MAIO: Oh, yeah. Well, they -- by "stunning" -- I'm using the term "stunning" and I know any physician's listening to me are cringing because essentially it's -- what it is is a very mild concussion. But stunning is kind of more -- it's not an incapacitating thing. You're not knocked out. Anyone who's ever fallen and hit their head hard knows what I'm talking about, the stunning effect. But it's -- you know, you hit your head hard, you understand what it means.

WEST: There has been some discussion in the testimony about punctate abrasions.


WEST: Let me show you exhibit 66. Are there punctate abrasions evident in this photo?

DI MAIO: They're right here. It's kind of washed out with the photograph. But you can see little reddish markings, and that indicates that there was impact with a surface, a flat surface, that was not really smooth like this wood here. If you hit your head on this wood here, you would not get punctate. You'd have to get something with a little non-flat surface, you know, a little edge to it.

WEST: Would concrete of the nature that's used in your everyday sidewalk have that kind of surface?


WEST: Is this injury consistent with Mr. Zimmerman's head having impacted a sidewalk?

DI MAIO: Yes, sir.

WEST: There is some -- we're just checking to see if you'd care for some water? If you do just ...

DI MAIO: Oh, no. No, no, no, no.

WEST: The punctate abrasion is that sort of granular-looking red stuff around the temple?

DI MAIO: Right. It's not smooth. It's an area right here and then a little here and a little here and a little here and a little here, that sort of thing.

WEST: There appears to be a noticeable lump or knot a little higher up.

DI MAIO: Right. Over here.

WEST: Does that appear to be a consequence of the impact? Who would you -- how would you describe that?

DI MAIO: A knot. No, hematoma. It's bleeding underneath the scalp.

WEST: Do you think it's likely associated with the impact that caused the punctate abrasions?

DI MAIO: Yes, sir.

WEST: Could that then be, those injuries caused by one or more impacts with the sidewalk?

DI MAIO: Yes, sir.

WEST: Let me show you state's exhibit 70, a view of the right side of Mr. Zimmerman's head, I believe. Do you see anything here that would suggest impact with a fist or the sidewalk?

DI MAIO: You could start to see this is that punctate, and there's a little adhesion over there. It's not a good photograph, unfortunately, so -- but again it's consistent with some impact of some form. WEST: This is another of the same side. This is in evidence as 71, a slightly different angle.

DI MAIO: You can see it. Here's the injury. See here? You can see the reddish areas.

WEST: Let's take a look at the other side of the head on the left side in exhibit 73. If I might take a moment, your honor, and approach the witness, so the witness can see the actual photograph.

DI MAIO: Oh, I can see. There's no problem.

WEST: What do you see in this photograph, Dr. Di Maio, that's consistent with blunt-force trauma?

DI MAIO: Again you see -- this is a washed-out photograph, but there's an area. There are marks right over here, too. I would assume a print photograph would show it better. But there's some punctate marks over here.

WEST: May I approach the witness just briefly and then I'll return?

NELSON: Yes, you may.

WEST: Just to show you this photograph itself, exhibit 73. If you see better in this what was on the projector, could you point that out to the jury?

DI MAIO: Yes, if you look right here, you can see an arc of punctate abrasions, and then kind of a pile area, and then another arc right over here.

WEST: Do you see signs or evidence of a -- of hematoma, bruising of some sort?

DI MAIO: There's suggestion, but it's not as distinct as on the other side.

WEST: Thank you. Let me approach one more time. I'd like to direct your attention, though, Doctor, to this area above the ear.

DI MAIO: That's the area I'm saying that looks like it's swollen in that area. But it's hard to say definitely.

WEST: I see. It's consistent with swelling as a result of blunt- force trauma?

DI MAIO: Yes, sir.

WEST: That area is this general area here?

DI MAIO: Right.

WEST: Dr. Di Maio, you have seen exhibit 79, the first photograph taken at the scene of Mr. Zimmerman's face?

DI MAIO: Yes, sir.

WEST: And what signs of trauma do you see in this picture?

DI MAIO: Well, you have to look at the original, but if you do, this appears bruised. But if you look at the outline of the nose here and it shows up, and there's swelling here and a little abrasion there.

WEST: Is this a better picture?


WEST: Maybe I could approach the witness.

NELSON: Yes, you may.

WEST: Thank you.

DI MAIO: OK. If you look at this, you can see there's congestion in the nose and there's an abrasion. But notice how the outline here is a smooth outline. Here it bulges out and then comes back. And if you then compare it to another photograph you see, that this is consistent with a possible displaced fracture because the next photo taken of him in police custody, the -- which is only a few hours later, the swelling is not as prominent.

And that's why I believe the EMS thought he had a fractured nose. And you can see there's a swelling right here. It's very prominent. It's just below the area where he's got a small abrasion.

WEST: Is this injury you see in this exhibit consistent with having been punched in the nose?

DI MAIO: Yes, sir.

WEST: This is exhibit 48. We'll put it on the projector and see if you can find the detail. This is represented as the photograph taken several hours later at the police department of Mr. Zimmerman's face. Can you point out to the jury what you're referring to?

DI MAIO: If you look now at him, notice that swelling appears to be gone. Well, it can't be gone if it's just blood. So this is strongly suggestive of the fact that what he had was a kind of a displaced fracture here and that, when he was maybe examined by the EMS or something, they just pushed it back, either consciously or unconsciously, and so now it's just in place. And it's being held there by the muscle.

WEST: Either way, whether or not the fracture was displaced or not, or even fractured, does the trauma that you see in that photograph and this photograph consistent with having been struck hard in the face?

DI MAIO: Right. And so it's there, and then, of course, there's another blow here.

WEST: I will show you ...



ASHLEIGH BANFIELD, CNN ANCHOR: If you want to witness a piece-by- piece evisceration of a prosecution's case, watch your television screen right now because the man on the witness stand is the granddaddy of medical examiners in the United States of America.

It's Dr. Vincent Di Maio who wrote the book on forensic pathology, and he's ripping each and every one of strongest points of the prosecutors' case moment by moment with science. I cannot wait to see the cross.

Let's listen.


DI MAIO: I think you have six, identifiable injuries, the two lacerations on the back of the head, the impacts in both temporal regions. That's four. The nose is five. And the forehead is six. And there may be others, but the photographs are not of the quality that you can safely say.

WEST: May have -- may there also have been impacts that, for one reason or another, may have landed, but didn't actually manifest itself in a visible injury?

DI MAIO: Right.

UNIDENTIFIED MALE: Objection. Speculation.

NELSON: Sustained.

WEST: In a fight situation where someone may be resisting the attack by someone else, would you expect them, for example, as they are being pushed toward the concrete to resist by their muscles or their back, trying to sit up, for example?

DI MAIO: I would assume so.

WEST: So consistent with what you see here, is it possible there may have been other impacts, but they weren't so pronounced because there was some ability to actually resist the full force of the impact?

UNIDENTIFIED MALE: Objection. Speculation.

NELSON: Overruled.

DI MAIO: Yes, I told you that, you know, also in addition -- you know, the head wasn't cleaned of blood in some of the photographs.