Thank you, ladies and gentlemen. Please be seated. Agent Martz, would you resume the witness stand, please. All right. You got enough water there? All right. Miss Clark.
All right, sir. Now, you indicated that you did not identify the substance found on the rear gate and on the sock or in your blood as EDTA because it did not present the full daughter spectrum for EDTA, correct?
And did you explain to him why you did not identify the substance on the rear gate and on the sock as EDTA?
Did he make any request of you that you conduct any of the experiments he outlined here in court today when you spoke to him on previous occasions?
Did he ask you at that time when he spoke to you on--previously in Washington or on the telephone whether or not you were aware of any validation studies conducted by Quantico?
And the information that was generated by Quantico concerning the 93 percent average EDTA extraction, that study--did it indicate that when you--your extraction method would on the average remove 93 percent of the EDTA from any stain?
I believe I--in looking it over this afternoon, it said very little EDTA remained in the second extract. It did not give a percent in the information that he received.
Okay. When it said that very little EDTA remained in the second extract, does that mean that in order to determine if your extraction methods were appropriate and efficient, that they extracted the EDTA using the method you used and then attempted to go back and extract it again?
And is that an appropriate method to use to determine whether an extraction method is efficient?
That is one way, yes. Another way would be just to quantitate absolutely how much you remove knowing how much you placed on the sample.
And by conducting the study that they did, was it essentially found that the extraction method you used was appropriate?
All right. Now, you indicated that you continued testing on February 22nd even though you had determined there was no EDTA from a preserved test tube and you went into another mode to do that testing?
Yes. I conducted a positive ion mode looking for the 160 daughter from the 293 quasi molecular ion or the m plus 1 parent ion.
Now, did you--was there something different about the method of testing you used on the 22nd from the method you had used on the 19th?
Well, with the instruments, you can look at the positive ions or the negative ions that are produced in the ionization. And the first day when I set up the experiment, I was looking for the negative ion, the EDTA form with the ion complex. On the second day or on the 22nd, I was looking for a protonated EDTA.
And why did you do that? What would that give you more than you already got from your previous testing?
Well, I determined that it was a little bit more sensitive. So I would be able to detect lower amounts of EDTA that may be present naturally in human blood.
Now, when you talk about doing these tests, sir, you indicated that you tested your own blood. Do you recall that?
Nevertheless, did you generate graphs showing the results of the testing on your own blood?
And did you generate graphs showing that your--showing your blood tested with EDTA and without?
Your Honor, I have here a series of four charts that I would like to be marked People's next in order, A, B, C and D.
The bottom chart, it would be what's called the total ion chromatogram or all the ions that were looked for. The top chart is the 160 ion which is a daughter ion of EDTA. It has the m/Z160, which indicates master charge 160.
Did you attempt then to determine whether or not you could get the full daughter spectrum, that is the 132 as well on the evidence of the sock?
And showing you 543-B, does this graph depict your attempt to see whether or not you could detect the full daughter spectrum in the evidence of the blood from the sock?
And you saw his--you heard his testimony concerning this graph that's now before the jury?
This particular graph depicts a lot of noise is all it depicts. As I mentioned before with the electro spray, everyone is running a 50-yard dash. Everyone is coming to the finish line about the same time. There are many, many, many chemicals in blood that are going to come across the finish line at the same retention time as EDTA. So we're going to get a lot of noise signal at that area. The noise in this case is no larger really than--than--it--it just doesn't increase anywhere, and where it increases may be slightly where Dr. Rieders was pointing out in the one area. That's only because everything was coming out of the instrument at one time and it caused electrical noise. This is not real peaks. This is electrical noise. This is very common in mass spectrometry. It's electrical noise. It is not signal. Any time you would identify something as signal, you would want something larger than the noise. There's nothing here that's larger than the noise. It's random noise that's very common in mass spectrometry, especially in electro spray where you're using different I should say electrical settings than you're using with conventional mass spectrometry. This is standard noise in electro spray mass spectrometry. This should never be considered signal or should never be interpreted as anything other than noise.
What you would want to do and what I did, and unfortunately I didn't print it out, but there was a mass spectrum taken of that particular peak, and it showed that it was just noise. Since there was nothing there, I didn't print it out. But for someone to try to make this into something other than noise is totally wrong.
In your opinion then, is his--scientifically speaking, was it scientifically and forensically inappropriate for Dr. Rieders to have interpreted this graph in the manner that he did?
KEY QUOTENow, you point out the issue with respect to retention time. And you recall that Dr. Rieders testified that at about the same time, there was what he determined to be peaks of significance by looking at the retention time. Do you recall that testimony?
And in the gas chromatograph machine, the column in that machine is used for separation purposes, correct?
And in that regard then, the time at which things come out or things pass through the column and get to the mass spec is of significance, correct?
In your machine, the LC tandem ms with electro spray, you have indicated I believe an analogy that it's kind of like measuring how fast people will go in a 50-yard run?
Well, it could be true in anyone's machine. It's just the perimeters that are set up with this instrument at this particular time. I'm using the mass spectrometer, the triple stage mass spectrometer for my separator, more so than I am the liquid chromatography part of it. The liquid chromatography is giving minimal separation. Everything is coming out pretty much at dead volume. That's the shortest time something can go through that column. But I can allow this to happen because I have the resolution capability of a triple stage mass spectrometer and I can only let a particular ion go through. So I'm using that as my resolving power and not my chromatography.
And you would use a liquid to push whatever material you want to test through that column; is that right?
And it's pushed through that capillary. When it's pushed through it, is some kind of electrical charge given to it?
Well, it's a combination of a lot of things. It's--they're very small droplets. They're being forced out of a small tube. There's other gases around there, and all this helps the very small droplets to evaporate.
And when that happens, when the small droplets evaporate, they have an electrical charge given to them?
Well, the electrical charges are on the particles and they're transferred from one to the other. But there's a lot of electrical charges that are transferred at that particular time, yes.
Well, so you can create an ion. A mass spectrometer isn't any good unless you can create an ion. You either need a positive ion or a negative ion in order to separate it and identify it.
All right. And then in your machine, I think you indicated--you mentioned something earlier called a quadrupole?
Well, it's a triple stage quadrupole. I have three quadrupoles, yes. That's something--it's a mass filter. It's used to separate out the different masses.
Okay. And the quadrupole, is it like four rods kind of like--it would be like four pencils through which the item--the material is passed?
And then you determine by changing the voltage of those poles what can pass through and what can't?
Well, that's where the collision takes place. That's where you break down that ion and produce the daughter ions, the 132 and the 160 ion.
It will let through what I select. In one case, I let just the 160 ion go through, and in another case, I let from mass 130 up to 295 go through so I could get the full daughter spectrum.
So in that way, you run the material through your machine and adjust the voltage so that you can pass through and select out 293, 160 and 132?
Well, you can do it that way. What I elected to do is allow the 293 to go through and then just look at the 160 or let the 293 go through and then look at the full daughter mass spectrum from mass 130 to 295.
Well, it's not the most efficient way, but it's the only way that I would look for it in order to identify EDTA. I mean, I could look for 132 by itself, but my purpose is to identify EDTA.
Well, it would just be another screening test. It would not positively confirm EDTA. What I need for the confirmation is the three ions I mentioned in a particular ratio. And the only way I can do that is to get the full daughter. If I look for them individually, it is not proof that the other compounds or ions are not there. In other words, if I have a camera and I look for one person, another person, another person, it doesn't prove that there aren't people between those people. So I need to look at the full spectrum to see if it's EDTA. If there's something there in the middle that doesn't belong, it's not EDTA. So I need to look at the full spectrum to determine whether or not it's EDTA.
You could be missing a lot of ions. There could be other ions there. There could be a 150, a 170. You don't know unless you look.
So if you look for only 132's, you could be missing other ions that would prove to you it was not EDTA?
All right. So in your--for the manner in which your machine works, the separation occurs in the areas of those four poles, the quadrupoles?
Well, some of the separation does take place in the chromatography, but very little. Most things are coming through a dead volume. The highest selectivity is in the quadrupoles, allowing only mass 293 to go through.
Okay. So in the column that you--in the way you use your machine, the column is not particularly used for separation purposes?
Okay. It does not have the identification properties or capabilities that Dr. Rieders' machine does, correct?
Okay. So given what you're saying, sir, the fact that in your machine, all material is pretty much going to pass through the column at about the same time as opposed to Dr. Rieders' machine in which things pass through the column at very different times, would it ever be appropriate to use retention time as a factor to determine whether or not you identify a compound?
Well, I mean, it could be used, but I certainly wouldn't give it much weight. I personally would not use that. I use the full daughter mass spectrum. The separation technique that I use is just simply to allow the electro spray ionization to happen, not to identify the compound. Now, certainly, the compound has to come out there. But all compounds or most compounds I would identify would come out there. So it just doesn't have what we call resolution, the ability to separate one component from the other.
Then would you say, sir, that the retention time in your machine is not a discriminating factor in terms of being able to identify one compound as opposed to another?
And do you think that--strike that. To your knowledge, has Dr. Rieders ever operated the electro spray?
And what impact, if any, would that have on the knowledge that retention time is not a discriminating factor in your machine?
Well, it could have some. But what you need to consider here is the fact that everything was coming out in about a minute. Now, under normal chromatography like I did the one day to differentiate the bloodstains, the chromatography was like 10 minutes. Generally, if you see something in chromatography that's coming out at about one minute, you should be able to realize that's pretty much dead volume and that everything else is going to come out there, and you wouldn't want to use that to help discriminate a compound.
Well, in other words, there's a certain flow through the column. If I inject something here, it physically takes a certain amount of time to come out the other end. So when I inject EDTA or anything else, it just races through the column and comes out in the minimum time and something can pass through that column. Now, retention time generally, you want something to be absorbed somewhat onto the column so it will take longer to pass through, it will react with the column as it goes through. So it will take a long time to come out. In this particular case, it's just passing through.
And that's the major difference between the machine he operates and the one you operate?
--the type of chromatography that I'm doing versus what the normal chromatograph person would expect.
Now, you heard Dr. Rieders testify that he was surprised that there was only a few minutes between each scan?
Pretty much. Unfortunately, I still try to maintain my proficiencies on the instruments in the laboratory even though I'm in a management role. I do actively operate the instrument.
Now, given that you would not--you said signal to noise. The random peaks that you see on the chart before you on 543-A, how would you characterize those?
Well, the first indication that you don't want to give much credence to this is the fact that we've got 10 to the minus fourth for noise. I mean, this is a large count. So someone that didn't know a lot about mass chromatography would want to know why do you have noise that's that large. I mean, that's a thousand ions or something. Why do you have electrical noise that's a thousand ions. I mean, that's the first thing if I didn't know anything about electro spray or how this was done, I would want to know that before I made any interpretation. Generally, with most instruments, your noise level is going to be very, very small. Now, electro spray, the manufacturer suggests that you use the higher settings because they determine that it works better that way. And this is not normal noise level that you would expect in a mass spectrometer, plus your noises increase by the fact that you're doing tandem mass spectrometry. So you're got two different techniques here that require you to have this very large noise. And any time you have noise that's a thousand counts high, you'd better be very, very careful before you try to interpret and make a peak out of that noise.
It's random noise. I mean, I certainly would want something at least three times the noise before I would even consider it to be a signal.
Okay. Yeah. We talked a little bit about that, the ratio of signal to noise. Does--can you--does that mean that the highest peak has to be at least three times higher than any of the smaller random peaks--
Showing you 543 B. C? Oh, that was B. C. Can you tell us what this graph shows, sir?
I'm sorry. 206. This is a known blood that I took and placed on a cutting of the sock.
Now, when you say the known blood that you took, that was from an EDTA tube, correct?
That is signal. When you have something that's--in this case, we have 10 to the fifth, six times 10 to the fifth, that's a large signal for--representing the ion 160, which is a daughter ion of EDTA. There's a substantial amount of that particular compound coming up at that scan 39.
Now, in this graph, I don't see any of the random little jagged peaks that we did on the last one where you found that there was no full daughter spectrum.
Well, if you have noise that's--that's an inch high and your signal is 10 feet high, on a relative scale, you won't see that. So what you do is take your 10 feet and you kind of bring it down, and the one inch of noise disappears. That's a very, very large signal and we're plotting it on the same scale. So the noise disappears.
So if you were to generate a graph that kept the noise in it, but wanted to also depict the relative size of the peak that we see here, would you have graph paper big enough?
Well, I mean, you can plot any of these things and that's why I plot it on that particular graph paper, the comparison of the ion counts for the blood and the questioned stains.
And going back to the evidence of the sock from the 160 daughter, okay, now, that's the evidence of the sock, correct?
You see the jagged lines because the signal is not that much greater than the noise.
Okay. Now, I want to show you 543-D. In 543-D, this is again the sock with the blood you put on it from the EDTA test tube, correct?
And here you're trying to see if you can detect in the known reference blood the full daughter spectrum?
Yes. And you can see on those traces the 132 ion, the 160 and the 293, those are all much larger than the noise.
Then looking at all of these together, sir--I'm going to try and show you if I can the two reference sample, that is the two known EDTA bloodstains that you put on the sock that shows the parent ion and the full daughter spectrum.
Now, by way of contrast, I'm going to show you 543-A and C. I'm going to show you the evidence, the blood taken from the sock itself. Okay. Now, this depicts your attempt to find the full daughter spectrum on the evidence of the sock?
And would you identify the full daughter spectrum on the sock based on what you see in these graphs?
And scientifically, sir, in your opinion, would it be appropriate to identify EDTA from the graphs and the results shown in these graphs?
All right. And you also did testing on the blood from the rear gate on February 22nd, sir?
And what kind of test did you perform on February 22nd on the blood taken from the rear gate?
The same as I did on the sock. I analyzed in the positive ion mode doing both the daughter spectrum of 293 looking at the 160 ion in the full daughter spectrum.
And is this an attempt by you to determine whether or not you can find the daughter 160 ion?
Now, how do you account for the random peaks that you--the jagged peaks below the one larger peak?
Now, the fact that you see that electrical noise and in addition to that one peak, what does that tell you about the strength of the signal for the 160 daughter ion?
Well, it's closer to the noise level or becoming very close to the noise level in the instrument.
And showing you 544-B. Is this an attempt by you to see if you can find the full daughter spectrum, that is the 132 as well as the 160, in the rear gate stain?
And are you able to identify anything that would allow you--are you able to identify the full daughter spectrum in the rear gate bloodstain?
Well, there's several possibilities. One is that it's not EDTA. Another would be that it's below my detectable limit.
Well, the graph is just strictly instrumental noise. There's no signal that's recognizable above the noise level.
And if there was 132 daughter below your detectable limit, could it have come from an EDTA test tube?
And based on the findings in the last two charts, sir, a and B, 544-A and B, on the rear gate stain, is there a full daughter spectrum?
Would you identify the substance found in the blood on the rear gate as EDTA based on that finding?
The K68, meaning the blood taken from the test tube containing Mr. Simpson's blood?
And in this case, you applied the blood taken from his test tube, his blood, EDTA blood onto the cotton swatch for the rear gate?
And showing you 544-D, did you then make an attempt to determine whether you could find the full daughter spectrum on the known stands, that is the cotton swatch on which you placed the reference blood from Mr. Simpson?
And showing you 544-D, can you tell us whether or not you were able to detect the full daughter spectrum based on the results on this graph?
Well, if--clearly seeing that the ions 132, 160 and 293 are all ions that come out approximately 30 scans that are all above the noise level.
I'm going to show you--all right. Those are the results of your testing of the cotton swatch on which you put the blood from the reference tube of Mr. Simpson, correct?
And based on these results, would you identify the substance found in his blood as EDTA?
All right. And then contrasting those--contrasting those results, sir, from the known--the blood that we know to have been taken from a reference tube containing EDTA, here we have the results of the blood recovered from the rear gate, the evidence blood. Based on the results in these graphs, sir, would you identify the substance--would you identify that a full daughter spectrum has been obtained?
And based on that fact, sir, and on the results shown in these graphs, would you identify the substance found in the blood on the rear gate as EDTA that came from a preserved blood tube?
Did you generate a graph to illustrate the results of all of the testing that you conducted on the 22nd?
Well, the--some of the results, not all of them. I didn't include the blanks, but most of the results. Some of them.
Can you interpret for us the results--soon as we can see them--shown in this graph that's been marked as People's 545?
The two blood samples, K67 and K68, which I prepared and placed on the sock and a cotton swatch, clearly demonstrate that EDTA is present in these samples. This is the amount that we would want to find in the sock and on the gate if we were to say that it came from preserved blood. But as you can see, the sock and the gate gave a very minimal response for this particular ion of EDTA. In my opinion, EDTA from preserved blood is not present on the sock and the gate. These stains did not come from preserved blood.
Now, you were asked on direct by Mr. Blasier whether or not you had tested any blood of Nicole for the presence of EDTA. Do you recall that question?
And did you test a swatch of the dress that contained blood as well as a swatch of the dress that did not?
And in your testing of that swatch that did not contain, did not contain blood, do you show those results here on this graph?
Yes. The K65, I ran the dress, one that was an area that wasn't blood-stained and the other area was blood-stained.
Well, I attribute it to the possibility that EDTA is present in the garment, either the garment or the dye that the garment is made out of.
And directing your attention to the bar just to the right of that, K65, is that the swatch of the dress that did contain blood?
Is that--does that bar appear to be higher to you than the bar that shows the testing of the swatch from her dress that was not blood-stained?
Well, I mean, it could be attributed to anything. I mean the instrumental technique, the way that I've set it up cannot distinguish between peaks of that height. I--I really didn't attribute it to anything.
Okay. Based on the methods that you were using, it was your determination--you had to make the determination as to whether or not the blood in the evidence came from a test tube with EDTA or not, correct?
And in that regard, the method you used, was it effective and efficient for that determination even though it did not permit precise quantification?
Yes, it was. I mean, in all the charts that I prepared and all the tests, I could clearly distinguish between preserved and nonpreserved blood. On two of the days, the testing in the negative ion mode, which required EDTA, the complex with iron, I got no signal whatsoever for EDTA. And again, on the 28th, when I performed liquid chromatography by itself, which EDTA had to bind with a copper compound, I received no signal for the EDTA. It was very easy to distinguish between the preserved and the nonpreserved blood.
Can you tell us, sir, whether or not you confirmed with the full daughter spectrum on the dress?
The dress I was able to get pretty much what I call sufficient daughter spectrum, and I think I dictated as traces of EDTA were indicated on the dress.
I can't remember which one I ran. I would have only run one of the daughters. I don't remember right now which one it was.
You don't remember which evidence stain you ran it on, whether it was the dress with the blood or without the blood?
Well, the significance is that levels of EDTA that are used in manufacturing can be identified with the procedure that I used.
So you do I--now, has anyone--no. Strike that. You do then identify EDTA as present on the dress Miss Brown was found in?
I think what I used was the term "Detected." The daughter spectrum wasn't the best. I could expect a little better spectrum, but in my opinion, it is EDTA on the dress.
That's correct. I did not receive any daughter spectrum at all in those two, plus I did not get results in the negative ion mode nor the results from the liquid chromatography, in my opinion, EDTA was not identified and those bloodstains did not come from preserved blood.
Now, there has been much said about the variability of the quantification in the runs.
From day to day. And I believe you indicated that it's true that a run will vary in quantity shown. For example, if I run a test today, it will come up a certain level. If I run that same evidence tomorrow, it will come up a different level. Is that a fair characterization?
If there is--now, let me ask you about that. There is one particular graph that has been shown to you by counsel, and I'll fish it out later, but it shows two runs on the same day. Do you recall that chart?
Well, I showed a multitude of runs on the same day. Yeah, I think I remember the one with two run on the same day, yes.
And it showed that on one run, you showed a very low level of EDTA and on another run, a very higher--a much higher level?
I think it was several--several hours, many hours and, you know, many runs on the instrument.
I don't know if it was exactly 30, but it was probably at least 20 samples. I ran a significant number of samples on the 22nd.
Now, sir, bearing in mind that variability, if you run all samples at the same time, will the ratio you get between their various amounts remain constant or remain reliable as a method of determining the relative amounts between them?
Okay. Let me ask another one. If you--the machine varies from time to time in terms of the quantity it measures?
Well, it's more the mass spectrometer becoming dirty. The column, because of interference, it can widen the peak and sometimes you can lose signal. But it's a very complex system. There's many reasons the signal can be reduced.
Be that as it may, if you run all the samples at the same time that you are attempting to compare, they're all going to be either depressed or heightened to the same degree?
But what I'm getting at is a little different, sir. Would it be valid in your opinion, would it be appropriate to compare an item run in the morning with a different item run later in the day for their relative amounts of EDTA?
Well, I mean, it depends on the amounts that we're looking at. If we're looking at parts per million, 1 part versus 2,000, you can certainly differentiate those types of analysis. If you tried to run 49 parts per million versus 50 parts per million, you couldn't differentiate those types of analysis.
Let me see if I can make my question a little clearer. If I take--let's say you took that gate stain and you ran it today.
And you come up with 2 or 3 parts per million, and then you run it tomorrow and you come up with only 1 part per million. When you run it today and you come up with 2 or 3 parts per million and you want to compare it to a known reference sample and you run them at the same time, you know, one right after another, is that ratio that you get reliable, in other words, one being a hundred times more than the other?
Well, I mean, it can be. I don't understand the question totally, but you certainly can do comparisons with ratios on the mass spectrometer.
I think what I'm getting at, sir, is, you--the--Mr. Blasier talked a lot about the variability of the quantification.
Because the difference between 1 part per million and a thousand parts per million, the instrument can very easily distinguish those differences. We were talking on one day a magnitude of 4, and between 1 part per million and a thousand parts per million, we have a magnitude of a thousand. So it's very easy to differentiate those types of differences.
KEY QUOTEBecause instruments do change over time. You don't know who else used the instrument. They do have electronics that have to be adjusted. You can compensate by running a standard to get the same signal, but you generally would want to compare samples run on the same day.
And when you compare samples run on the same day, do you have a valid comparison between the amounts? In other words, does it give you an accurate assessment in relative terms as to a large amount versus a small amount?
Now, you indicated that you also did testing on A--another form of chromatography. Was that the high pressure--
Now, as a result of these tests, the high--high pressure? High pressure liquid or high-power?
As a result of this second--this third test, the results of this third test told you what with respect to the question you were asked as to whether or not the blood on the rear gate and on the sock could have come from an EDTA tube?
I got the same results that I got the other two days. The stains in question from the gate and the sock did not come from preserved--EDTA preserved blood.
Now, I'm going to show you the graphs that were generated as a result of those tests.
All right. And then I'm going to show you--and what does that indicate, sir, that no other peaks were detected?
And now I'm going to show you People's 546-B, and this is your testing of the evidence blood from the sock on February 23rd. Can you tell us what does this graph indicate to you?
Again, this is the injection and that's the solvent coming out and no other peaks were identified. That large peak is the solvent peak.
Okay. Now, I'm going to show you, sir, a graph run on the reference blood of Nicole brown, People's 546-C? Am I at C? 546-C. Okay. This is the testing on the reference blood from Nicole brown. And would you tell us whether or not, based on these results, you would determine and conclude that EDTA from preserved blood is present?
Well, from this test alone, I wouldn't conclude that. But certainly, there's indication that EDTA is present.
And showing you 546-D, this is the testing of the reference blood of--taken from the test tube for Mr. Simpson. Can you tell us what the results indicate to you in this test?
In this case, sir, having already conducted the negative ion mode and then the positive ion mode test and forming a conclusion that EDTA from preserved blood was not present in the evidence stains on previous dates, did this test operate, this HPLC test operate to confirm or corroborate those conclusions?
And showing you this graph, sir, does this depict accurately the results you obtained on February 23rd?
Okay. The two known reference samples from the Defendant and Miss Brown are to the far left, sir?
That's correct. That's the--the counts that represent where EDTA comes out in an area on the chromatograph run that day indicating the presence of EDTA.
And the Q206 and Q204 that we see to the right of those for the sock and the rear gate indicates?
The sock and the rear gate did not give a signal or a response where EDTA would come out on those chromatograms.
And then to the right of that, you have a 5 PPM, 5 parts per milligram? What's that?
And does that indicate that you can detect an amount as low as 5 parts per million?
Well, I didn't use this quantitatively. But the range would be around 5 parts per million for that sensitivity of the instrument.
Then based on all of the tests that you conducted, the negative ion mode, the positive ion mode and the HPLC, were all of those tests consistent and uniform in their results?
That EDTA was present in the K67 and K68 blood samples and was not present on the sock and the gate.
For someone to try to make this into something other than noise is totally wrong.
These stains did not come from preserved blood.
Because the difference between 1 part per million and a thousand parts per million, the instrument can very easily distinguish those differences. We were talking on one day a magnitude of 4, and between 1 part per million and a thousand parts per million, we have a magnitude of a thousand.
In your opinion then, is his--scientifically speaking, was it scientifically and forensically inappropriate for Dr. Rieders to have interpreted this graph in the manner that he did?
In my opinion, it was, yes.