[DIRECT EXAMINATION BY MR. HARTZLER]
Q. Mr. Cadigan, where are you employed?
A. I'm a special agent of the Federal Bureau of Investigation, and I'm currently assigned to the Firearms and Tool Marks Unit of the FBI laboratory.
Q. What are your responsibilities?
A. As a member of the Firearms and Tool Marks Unit, I have three areas of responsibility. One is serial number restoration, one is firearms identification, and one is tool-mark identification.
Q. How long have you been employed as a tool-marks examiner, qualified as a tool-marks examiner for the FBI?
A. 20 years.
Q. Can you tell the Court and ladies and gentlemen of the jury what a tool- mark comparison is?
A. Tool-mark comparison or tool-mark identification deals with the comparison of a mark left at the scene of a crime with a particular tool. For instance, in a burglary in which a crowbar is used to pry open a window, tool- mark comparison would be looking at the mark on the windowsill and comparing that with marks made by a known crowbar to determine whether or not the mark left on the window sill during the burglary was produced by a particular tool to the exclusion of any other tool produced.
Q. Did you conduct a tool-mark comparison for this case?
A. Yes, sir, I did.
Q. And did it involve a padlock and a drill bit?
A. Yes, it did. * * *
Q. You said at the beginning of your testimony that you did a tool-mark comparison for this case, and we're going to present you with various items of evidence; but could you just in general terms explain to us what it was that you did?
A. I received a padlock that had some drilling impressions in it, and I received some drill bits; and the request was to determine whether or not the drill bits that were submitted produced any of the marks contained on the padlock.
Q. Upon receipt of the padlock, did you measure the hole?
A. Yes, I did.
Q. How large was that hole?
A. It was 1/4 of an inch in diameter. That would be considered a class characteristic. All drill bits that were 1/4 of an inch in diameter could have made that particular impression.
Q. So you were able to conclude that you needn't waste your time on 3/8 drill bits, and so forth.
A. That is correct.
Q. When you obtained the padlock, did you see any unique or significant markings?
A. Yes. I noticed that the padlock had two drill impressions in it, one that was shallow and one that was much deeper.
Q. And from these impressions, did you see anything that you would characterize as a tool mark?
A. Yes. In both the shallow-drilled area and in the deep-drilled area of the lock, I noticed tool marks of value present. * * *
Q. Starting from the left side of the chart, can you describe for us what's depicted?
A. Yes, I can.
Q. Please proceed.
A. On the left side of the chart is the picture of the lock, padlock. The second picture at approximately 10 power is a picture of the lock cylinder that has been removed from the padlock, and it shows both the shallow drill-bit impression and the deep impression. To the right of that picture at approximately 20 power is a closer photograph of the tool mark or the drill-bit impression. And then to the far right at approximately 40 power is a much closer picture of tool marks that are contained at the bottom of a lock cylinder of the padlock.
Q. Can you describe for us what the tool marks are?
A. Yes. Those marks would be the scratches left by the tip of the drill bit as it drilled the lock cylinder. * * *
BY MR. HARTZLER:
Q. Very well. Could you resume the stand, then, for a moment. Mr. Cadigan, what items did you have or suspect tools did you have to compare to the markings down in that hole in the bottom of the padlock?
A. I had two drill bits to compare with the marks found in the lock cylinder of the padlock.
Q. It's obvious, but the size of those two drill bits was?
A. 1/4 of an inch in diameter.
Q. What did you do with those drill bits?
A. For each of the drill bits, when I received them, I put each of them into a drill and then made-- drilled small holes into pieces of lead to determine what kind of marks each of the drill bits made and then to compare those marks that each of the drill bits made, that I made with them, to the marks found in the lock cylinder.
Q. Why could you not simply make the comparison directly from the drill bit tool marks in the cylinder?
A. Because in tool-mark examinations, the best examination is like item to like item; in other words, a drill-bit impression to another drill-bit impression, as opposed to a drill-bit impression to a drill bit. * * *
Q. Look in the box to your right hand and see if you can find Government's Exhibit 151B.
A. Yes, sir.
Q. This has previously been admitted into evidence. Can you tell us whether you can identify that particular item.
A. Yes. This is a -- one of the drill bits that I received in the laboratory for comparison with the padlock, the drill-bit impressions on the padlock.
Q. Did you examine the tip of that drill bit?
A. Yes, I did.
Q. Prior to making the drill-bit impressions you just described?
A. Yes, sir.
Q. And did you photograph the very tip of the drill bit?
A. Yes, I did.
Q. Did you notice any unique characteristics about that drill-bit tip?
A. I noticed that it was worn.
Q. I want to show you what's been marked as Government's Exhibit 155 and ask if you can identify this.
A. Yes, sir.
Q. This is a picture that was taken of the drill-bit impression -- of the drill bit itself?
MR. HARTZLER: I move the admission of Government's Exhibit 155.
MR. TRITICO: No objection.
THE COURT: 155 received. It may be displayed. * * *
MR. HARTZLER:
Q. Do you have it? Again, can you point out to us those unique characteristics that you found on the tip of the drill bit? And just to orient everybody, tell us what direction we're looking at on this.
A. The tip of the drill bit is pointing at the camera or at the viewer.
Q. So the bit is coming toward us, in effect.
A. That's correct, yes, sir.
Q. And you said that there were some characteristics that you discerned on the tip.
A. Yes, sir.
Q. Please point those out to us using that little light pen.
A. All along the edge of the cutting edge of the drill bit, there are signs of -- and marks of wear. In other words, the --
Q. Along here?
A. Yes. Along where the -- the finger is pointing. Also in these areas.
Q. For some reason, you seem to have a black color now with your pen.
A. Yes, sir.
Q. It's not showing up on my screen, but it's fairly clear. Where my finger is pointing, you're talking about that being the cutting edge of the drill bit?
A. Yes, sir.
Q. And the -- that's where the irregularities are that produce the drill- bit impressions. Is that correct?
A. Yes, sir.
Q. Now, you also said that you used this drill bit to generate some impressions in some test material.
A. Yes, sir.
Q. What test material did you use?
A. Lead.
Q. Why?
A. Because lead is a soft metal and does not alter significantly the drill bit as you take the impression.
Q. All right. I want to show you what's been marked as Government's Exhibit 153, which is the chart behind you. * * *
A. Yes, sir.
Q. And does that depict the drill-bit impressions that you produced?
A. It's a series of photographs of the drill-bit impression that I produced, yes, sir.
Q. At different magnifications?
A. Yes, sir.
MR. HARTZLER: I move the admission of Government's Exhibit 153.
MR. TRITICO: No objection.
THE COURT: 153 is received. You may display it. * * *
A. As I stated, this is a series of four photographs at differing magnifications of one of the drill-bit impressions that I made of Government's Exhibit --
Q. 151B?
A. -- 151B. This is the picture of the piece of lead showing the red arrow, the particular impression, that same impression at 10 power and at 20 power and at 40 power, showing the lines or striations or scratches that are left by the drill bit as it starts to cut and mark the metal.
And the tool-mark examiner compares these scratches with scratches on whatever he is examining.
Q. Before you sit down again, would it be difficult for you to hold up 152 beside that chart and explain what item you're comparing?
A. 152 being?
Q. That's the other large chart that we have, that was just placed down off the easel. On the other side, maybe.
A. And your question?
Q. I'm asking if you can use these two charts to show the Court and the ladies and gentlemen of the jury what it is that you're ultimately going to compare, if everyone can see.
A. Yes. I'm comparing the scratches or striations left by the tip of the drill bit in the lead with the scratches or striations that are present on the lock cylinder to determine whether or not this drill bit produced those scratches or striations. * * *
Q. Mr. Cadigan, how did you accomplish that comparison?
A. By the use of a comparison microscope.
Q. Can you describe for us what a comparison microscope is?
A. Yes, sir. A comparison microscope is two microscopes joined by an optical bridge or optically with a stereoscopic viewer; and what that allows the tool-mark examiner to do is to look at two items under high magnification to determine and compare the scratches or striations present on both of them at the same time, side by side, in order to make a determination whether or not a particular tool made a particular mark.
Q. Now, you obviously conducted that comparison for or between the marks you saw on the padlock and the marks you produced from the drill bit, 151B. Is that correct?
A. That's correct.
Q. What did you find?
A. I found that the marks present on the deep-drilled impression on the padlock were produced by the drill bit, Government's Exhibit 151B.
Q. And did you produce a chart or photograph of that comparison?
A. Yes, sir, I did.
Q. I'd like to show you what's been marked as Government's Exhibit 157 and ask if this is the comparison exhibit that you produced.
A. Yes, sir, it is.
MR. HARTZLER: I'd move the admission of Government's Exhibit 157. * * *
MR. TRITICO: I have no objection. * * *
THE COURT: 157 is received.
MR. HARTZLER: Thank you. And may we publish it, your Honor?
THE COURT: Yes.
BY MR. HARTZLER:
Q. Can you see on your screen now the right side of the demonstrative exhibit you've produced?
A. Yes, sir.
Q. And that shows -- shows us what?
A. That shows us a portion of the drill-bit impression that I made with Government's Exhibit 151B.
Q. So that's simply a portion -- and in fact of the final photograph you have on the chart that's displayed in the courtroom now?
A. It is a portion of one of them.
Q. Now we're showing you the left side of your demonstrative exhibit. What is that?
A. That is a portion of the tool marks present on the drilled-out portion of the lock cylinder of the padlock that I received.
Q. So that's in effect a section of the final 40-power photograph that we saw on the chart that was up there a moment ago from the inside of the padlock?
A. That is correct.
Q. If we show them both at the same time, they show your comparison?
A. Yes, sir.
Q. Describe, using your light pen, as best you can what it is you saw looking through your comparison microscope.
A. As I mentioned, the right side of the photograph -- on this right side, I am looking at this area here with these lines or scratches that go in this direction and comparing them with lines and scratches that I found on the padlock. And this particular photograph, I took with the comparison microscope.
Q. And based on that comparison, what was your conclusion?
A. That the Government's Exhibit 151B -- this drill bit -- produced marks that were contained in the padlock that was submitted.
MR. HARTZLER: Nothing further, your Honor.
CROSS-EXAMINATION BY MR. TRITICO: * * *
Q. Now, you work in the FBI lab; is that right?
A. That is correct.
Q. The FBI lab is currently not accredited by any accrediting agency; right?
A. That is correct.
Q. You've been pending accreditation for over three years; right?
A. I don't know of the time, but we are in the process of applying for certification from a crime laboratory directors association; that is correct.
Q. This would be the first time the FBI lab has ever been accredited; is that correct?
A. That is correct.
Q. Now, you had two drill bits that were submitted to you for examination;
am I correct?
A. That is correct.
Q. Two 1/4-inch bits?
A. Yes, sir.
Q. Do you know where those drill bits came from?
A. I was told where they came from, but I don't have any personal knowledge.
Q. Right. And if I understand your testimony correctly, you examined two areas on this one lock that both had bit -- drill -- strike that. That both had tool-mark impressions; correct?
A. Yes, sir.
Q. One you called a shallow area and one you called a deep area; right?
A. That is correct.
Q. Now, you couldn't match the shallow area with either one of the two bits that you had; right?
A. That is correct.
Q. It could have been one or both or not either one; right?
A. That's correct.
Q. That could have been any drill bit; right?
A. Yes, sir.
Q. Now, one of the bits that you couldn't match the shallow area with is
the drill bit that's in evidence as 151B. Is that right?
A. Well, the one that I identified was 151B.
Q. I'm sorry. I'm still talking about the shallow area. You examined 151B with respect to the shallow-impression area; right?
A. Yes, sir.
Q. And it didn't match. You couldn't match it with that area; right?
A. No, sir.
Q. Where is the other drill bit?
A. It's in this box.
Q. Still in that box?
A. Yes, sir.
Q. Where is the photograph that you took of the end of the other drill bit, like the one you have of 151B?
A. Well, I have several photographs of it.
Q. Okay. Who made those bits? Do you know?
A. One of them, I know the manufacturer. The other, I do not.
Q. Okay. Do you know the manufacturer of the one that you have identified today as making the deeper hole?
A. No, sir.
Q. Who made the one you do know?
A. Vermont American.
Q. Did you go to Vermont American in preparation for your investigation in this case?
A. Yes, sir, I did.
Q. When did you go there?
A. Approximately three or four months ago.
Q. And when you went there, did you find that they -- well, how many drill bits, 1/4 drill bits, did you find they make in a year?
A. They -- I don't recall the exact number, but it was in the millions.
Q. Okay. And these are tooled on a tool-and-die machine? Am I correct? Is that a fair statement?
A. It's a several-step process to produce drill bits like this.
Q. Well, they don't have a person just cutting them out all by himself. They're all done on a computerized machine; right?
A. They're done on several machines, yes, sir.
Q. And the machines are all keyed to make the exact same bit millions of times over, so they don't have to keep retooling it every time. Right?
A. The machines are set up to produce drill bits that match their specifications. That's correct.
Q. And they all come off the machine the same; right?
A. Yes, sir.
Q. And then they go through a process of sharpening the very end, the one you photographed; right?
A. Well, the sharpening is part of the production of the drill bit, yes.
Q. It all comes through the machine that's keyed to tool to make everything the same; right?
A. Yes, sir.
Q. How many other bits from this company did you get -- When was this one made? Do you know?
A. When was it made? I don't know.
Q. How many other bits did you test from this company when you were conducting your investigation into this case?
A. Approximately 75.
Q. And -- but -- without knowing what year it was made, you don't know if you were really testing one that was tooled on the same tool and die; correct?
A. That's correct.
Q. And since you don't know who made the bit that you identify here today as making the deeper impression, you couldn't test any of those bits against it; right?
A. Since I didn't know the manufacturer, I couldn't obtain bits from a manufacturer I didn't know. No, sir.
Q. Absolutely. Could be millions of bits came off the same tool and die that made that bit, 151, I think. Right?
A. 151B?
Q. 151B. Could be millions of bits that came off the same tool and die, make the exact same bit. Right?
A. I would imagine there is.
Q. Now, when you test -- when you look at these bits on the microscope, do you know how -- it doesn't tell you how old the bit is, does it?
A. No, sir.
Q. Doesn't tell you how long the bit was in the yellow box, does it?
A. No, sir.
Q. Doesn't tell you how long the bit was in the house or place from which it was seized, does it?
A. No, sir, it does not.
Q. Doesn't tell you who drilled the hole that you're testing the impression on, does it?
A. Oh, no, sir. * * *
Q. Now, when you began your work on these tool-mark impressions, you were told that this bit and the other bit that you looked at were seized from Terry Nichols' home; right?
A. Most likely, yes, sir.
Q. Were you told that before you did your work, or after?
A. I don't recall.
Q. Could have been before you even started; right?
A. Yes, sir.
Q. You knew what you were working on when you got it; right?
A. Yes, sir.
MR. TRITICO: All right. Thank you. * * *
REDIRECT EXAMINATION BY MR. HARTZLER:
Q. Mr. Cadigan, you said that -- pardon me -- some drill bits are manufactured in the millions. Is that correct?
A. Yes, sir.
Q. So that the manufacturer of this particular quarter-inch drill bit that's 151B could have a number of -- large, large number of siblings. Is that fair?
A. Absolutely.
Q. How is it that you can distinguish this particular drill bit from all of the siblings?
A. From the unique microscopic marks that this drill bit leaves when I -- or when a test impression is taken, when the hole is drilled.
Q. How is a drill-bit tip manufactured?
A. It is the -- in the finishing process of the drill bit, the drill bit itself is ground using a grinding wheel. This grinding wheel has randomly placed particles that impart a random pattern of marks or striations to the tip of the screwdriver -- tip of the drill bit. And it is those marks plus the use and abuse marks, the wear marks, present on the drill bit, specifically Government's Exhibit 151B, that allowed me to identify this drill bit with the padlock.
Q. Would you expect two consecutively manufactured drill bits to produce different drill-bit impressions?
A. No, sir.
Q. Why is that?
A. Because of the finishing process. When the grinder is applied to the drill bit, it strikes the drill bit in a random pattern. Logically, if two drill bits were to produce the same exact microscopic scratches on a surface that they were used -- logically, you would expect that to be in two that were consecutively produced. I looked at -- went to a manufacturing plant, Vermont American, obtained drill bits that were consecutively produced, took impressions of them, and compared them. They were not the same.
Q. I think maybe you misunderstood my question. I was asking if two consecutively produced drill bits would produce drill-bit impressions.
A. That is correct. * * *
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updated 1/20/99