Commonwealth v. Read — Trial ArchiveNicholas Roberts - Direct/Cross/Redirect/Recross
295 linesJUDGE CANNONE: All right, Dr. Faller, thank you. And I'm sorry I gave you such a — okay, I'm sorry if I — thank you, thank you. Your next witness, Mr. Lally?
MR. LALLY: Yes. The Commonwealth calls Mr. Nicholas Roberts to the stand.
COURT OFFICER: Muted — sidebar. Do you swear to tell the truth, the whole truth, and nothing but the truth, so help you God?
MR. ROBERTS: I do.
JUDGE CANNONE: Thank you. You can have a seat. I just need you to keep your voice up really loud — if you're too soft we have to turn off the air conditioning and everyone's going to get mad.
MR. ROBERTS: No problem.
JUDGE CANNONE: All right, Mr. Lally, thank you.
MR. LALLY: Good afternoon, sir.
MR. ROBERTS: Good afternoon.
MR. LALLY: Would you please state your name and spell your last name for the jury, sir?
MR. ROBERTS: Sure. My name is Nicholas Roberts, R-O-B-E-R-T-S.
MR. LALLY: And what is it that you do for work, sir?
MR. ROBERTS: I'm currently employed with a company called Thermo Fisher as a field service engineer.
MR. LALLY: And how long have you been doing that?
MR. ROBERTS: Since November of last year.
MR. LALLY: And so prior to that — prior to November of last year, 2023 — where did you work before that?
MR. ROBERTS: I was in the Massachusetts State Police crime lab in the toxicology unit.
MR. LALLY: And how long did you work in the toxicology unit at the Massachusetts State Police crime lab?
MR. ROBERTS: Since October of 2014.
MR. LALLY: Now if I could turn your attention to prior to joining the Massachusetts State Police — can you talk a little bit about your educational background, where did you go to school and what did you go to school for?
MR. ROBERTS: Sure. I have a bachelor's degree in applied forensic science with a concentration in chemistry and toxicology from Mercer University — that's in Erie, Pennsylvania — and then I also have a master's degree in forensic toxicology from the University of Glasgow in Scotland.
MR. LALLY: Now after receiving your degree from the University of Glasgow in Scotland, where did you go?
MR. ROBERTS: I returned home to the British Virgin Islands, where I taught at a community college.
MR. LALLY: And what did you teach there?
MR. ROBERTS: Mainly chemistry and a term or two of physics.
MR. LALLY: And then following your teaching in the Virgin Islands, where did you go from there?
MR. ROBERTS: I was hired then at the Massachusetts State Police crime lab.
MR. LALLY: Now when you were initially hired at the Massachusetts State Police crime lab, you were working initially as a forensic scientist one, is that correct?
MR. ROBERTS: Correct.
MR. LALLY: And can you explain to the jury sort of what your duties and responsibilities are — what your work looks like as a forensic scientist one?
MR. ROBERTS: So as a forensic scientist one you're essentially going through all the trainings that they provide at the lab. We do a number of different types of testing, mainly on blood and urine, looking for the presence of drugs and alcohol. We also do serum conversions and retrogrades. So during my training period I started as an FS1, so that went up until I was fully signed off to actually write reports that would be issued to ADAs across the whole of Massachusetts — at which point I became a forensic scientist two.
MR. LALLY: And so what is the difference, sir, between sort of your work as a forensic scientist one versus your work as a forensic scientist two?
MR. ROBERTS: So essentially as a two you're fully trained and you're able to do all the testing that we do in-house. We also are able to go and give testimony based on the reports that you write, whereas as a forensic scientist one you're still in that training process.
MR. LALLY: And did you work essentially as a forensic scientist two from that point in time till the time that you left the lab in November of 2023?
MR. ROBERTS: Yes.
MR. LALLY: Now with reference to — while you were working at the lab, was there sort of an ongoing continuing educational component?
MR. ROBERTS: Yes, so we would habitually receive articles based on different discoveries within the forensic field — different ways they would find certain types of drugs in different bodily fluids. It's always a revolving door when it comes to drugs being discovered as well as being manufactured — what's listed on the street, et cetera — we would often get different articles, just research papers, based on what they're doing to discover these things within the matrices that we are looking at.
MR. LALLY: Now in addition to that, while you worked at the lab — are you familiar with the term proficiency testing?
MR. ROBERTS: Yes.
MR. LALLY: What if any proficiency testing would you undergo while you were at the lab?
MR. ROBERTS: So we received both in-house and external proficiency tests. Essentially the process would be just the same — the only difference would be we'd have internal people sending us samples as if it came from an external source. And then the external proficiency testing that we received is actually part of our accreditation, so it came in just like regular samples and we would test it accordingly per protocols.
MR. LALLY: And as far as the proficiency testing that you undertook over the course of your time at the lab, did you pass each of those tests?
MR. ROBERTS: Yes.
MR. LALLY: Now you mentioned a little bit as far as accreditation — with regard to the lab, what if any accreditation did the state police crime lab have?
MR. ROBERTS: We had accreditation — it's an internationally recognized accreditation board for forensic scientists as well as any kind of lab in particular, and the branch that our lab would fall under — we have a certain set of rules that we have to adhere to — mainly it's a standard known as ISO 17025 — but we have a different accreditation board and they have narrower requirements because of the type of lab that we are.
MR. LALLY: It may be pretty well understood, but as far as the accreditation is concerned, that's done by an external entity, is that correct?
MR. ROBERTS: Yes.
MR. LALLY: Now with regard to the lab, as far as your assignment of work — by the time that you left the lab, about how many forensic scientist twos were working within the lab in your toxicology unit?
MR. ROBERTS: By the time that I left? So within the toxicology unit, there was one more — at the time that I left.
MR. LALLY: And as far as you and sort of the other forensic scientist twos — at the time that you worked at the lab, was there some sort of rotation, or how were you assigned your work as it related to your work in the toxicology unit?
MR. ROBERTS: So throughout my time there we had more forensic scientist ones and twos, and we would delegate each type of assignments — different types of testing — on a monthly basis we'd get a different group of tests that we would perform throughout that month, and it would rotate to the next person at the end of the month, so that's how we did the testing.
MR. LALLY: Now sir, if I could turn your attention to May of 2022 — you were working with the lab at that time, is that correct?
MR. ROBERTS: Yes.
MR. LALLY: Were you assigned to serum conversions at that particular time?
MR. ROBERTS: I was, yes.
MR. LALLY: And at some point were you specifically assigned to a case involving a Miss Karen Read?
MR. ROBERTS: Yes.
MR. LALLY: Now as far as a serum conversion is concerned, if you could explain to the jury sort of what goes into that process — what is it that you're reviewing or looking at, and how is a serum conversion performed?
MR. ROBERTS: Sure. So with serum conversions, usually what happens is that we get hospital results — so that would be the police or the ADAs would get results from the hospitals for whoever was attended to — we'd get the results, and usually hospital alcohol results use serum in order to test alcohol. Serum is essentially the liquid portion of blood. Let's say for instance you fall and you cut yourself — that red stuff that comes out, that has serum within it. What the hospital does is they centrifuge it, or spin it very fast, in order to get the red blood cells, the white blood cells, and all kinds of heavier materials out of that blood, and what's left is serum. So they use that to test their alcohol.
MR. ROBERTS: What studies have shown is that you actually tend to have a higher alcohol concentration in serum than in blood. So what that means is that due to the chemical nature of alcohol, it likes to stay in that liquid portion more than throughout the whole blood. So the serum conversion essentially is able to convert the alcohol content from that serum that we get from the hospital into what it would be in whole blood.
MR. LALLY: And did you have occasion to perform a serum conversion in regard to Miss Read's medical records?
MR. ROBERTS: Yes.
MR. LALLY: May I approach the witness?
JUDGE CANNONE: Yes.
MR. LALLY: I'm showing you a document — just ask you to review that — finished? Did you recognize that, sir?
MR. ROBERTS: Yes.
MR. LALLY: And what do you recognize that as?
MR. ROBERTS: So this is the serum conversion report that I made — the calculations were made on May 3rd of 2022.
MR. LALLY: And as far as the result that you received — so what kind of materials did you receive in order to perform that analysis?
MR. ROBERTS: We got the medical records.
MR. LALLY: Yes — apologies — I want to show you what's been marked as Exhibit 106, and directing your attention to this last page contained in this document here — is that a portion of the medical records that you reviewed in regard to Miss Read's serum alcohol level?
MR. ROBERTS: Yes.
MR. LALLY: And if you could — what was reported in the medical records that you reviewed in your serum conversion analysis as far as the level?
MR. ROBERTS: The level was at 93 milligrams per deciliter.
MR. LALLY: And so with regard to that 93 milligrams per deciliter — I'm sorry, was there also a time that that specimen was collected as far as your review of those records?
MR. ROBERTS: Yes.
MR. LALLY: And what was that time, sir?
MR. ROBERTS: It was at 9 in the morning — 9:08.
MR. LALLY: Now as far as — just in terms of the general term as far as forensic science, what you did at the lab — can you explain what that term means, or how — what you did in relation to that?
MR. ROBERTS: What do you mean specifically?
MR. LALLY: Let me — that was very poorly phrased. Let me try to restate that. What is your understanding of forensic science? Can you explain that?
MR. ROBERTS: Oh, forensic science is essentially a scientific study based on anything dealing with the law — so whether it comes to ballistics or DNA analysis, or toxicology like I did, anything focused or based on the law or for legal purposes, essentially that's what forensic science kind of encapsulates.
MR. LALLY: Then forensic toxicology — would that sort of be a subset of forensic science?
MR. ROBERTS: Yes.
MR. LALLY: And can you explain to the jury sort of what's your understanding, based on your training and experience, what is forensic toxicology?
MR. ROBERTS: So toxicology in general is essentially just a study of poisons, plainly speaking. So anything that be harmful to the body, essentially that would be toxicology — because you also not only have forensic toxicology but you also have like environmental. And forensic toxicology is just — like I said again with the forensic — just basing it on things for legal purposes.
MR. LALLY: Now through your training and experience, you're familiar with the difference between a serum plasma level versus a whole blood level?
MR. ROBERTS: Yes.
MR. LALLY: And can you explain to the jury sort of what your understanding is of each and what if any differences there are between the two?
MR. ROBERTS: So just plainly, your serum plasma level — or the serum plasma, as it's called — it could be referred to as either, or one or the other. So it's just the alcohol level in your serum, whereas your whole blood is your alcohol content, or regular BAC, in the whole blood. The difference between the two is, like I said previously, in your serum or plasma that alcohol content would be higher than it would have been in the whole blood.
MR. LALLY: Now as far as the milligrams per deciliter, how that's reported in the Good Samaritan medical records referencing Miss Read that you reviewed in this case — is that typical as far as how hospitals would report sort of the serum plasma levels?
MR. ROBERTS: Yeah, from my experience and all the times that I've seen serum conversions come through the lab, milligrams per deciliter are the units that they use from the hospital.
MR. LALLY: Now as far as that 93 milligrams per deciliter — with regard to serum conversion — what if anything are you then able to do to convert that to a BAC, or a blood alcohol concentration?
MR. ROBERTS: So based on some studies, they came up with a few different conversion factors. Knowing that the blood alcohol content would be higher than the serum plasma content, they're able to apply different conversion factors to the numbers that we would get in serum. And we usually give a low, an average, and a high — being that it's kind of hard to say what one particular person's conversion factor would be between the two, since it's dependent upon like age, sex, water content, what you had to eat that day. So it's harder to pinpoint; therefore we give a range of what it could possibly be — pertaining just in case a person's conversion would be a lot lower or higher, so we give a range.
MR. LALLY: And as far as those different conversion factors, where do those come from?
MR. ROBERTS: It's based on some studies. I don't remember the actual names of the papers, but they are based on studies throughout the forensic world when it comes to looking at specifically testing blood and serum to find that conversion factor.
MR. LALLY: And as far as those studies are concerned, do they come from sort of different population bases? Is that correct?
MR. ROBERTS: Yeah, so that's how they're able to get the range of conversion factors that they use.
MR. LALLY: Now as far as the water within the serum, or sort of how that works with the centrifuge — what if any relationship does that have to the reading that you get or the conversion factors that you use?
MR. ROBERTS: So the water content — essentially, the serum being the liquid portion of the blood, water is also liquid, it makes up some of that serum that you get from it. Therefore your higher water content, essentially the lower the concentration could be — or lower or higher, depending upon whether or not your water content in that sample is lower or higher.
MR. LALLY: So as far as those different conversion factors that you're using, this is essentially a mathematical calculation — is that right?
MR. ROBERTS: Yes.
MR. LALLY: And so the different conversion factors that you're using for the low, the average, and the high — what are those conversions?
MR. ROBERTS: So the low is 1.18, with the average being 1.14, and then the high being 1.12.
MR. LALLY: So based on your analysis, as far as the medical records — using those three conversion factors, what if anything did you come up with as far as a low, an average, and a high for the 93 milligrams per deciliter?
MR. ROBERTS: So the values that were calculated — the low was at 0.078 g percent, the high was 0.083 g percent, with the average being 0.081.
MR. LALLY: Now sir, with reference to the alcohol that's reported in the records — are you familiar with, are there different types of alcohol?
MR. ROBERTS: Yes.
MR. LALLY: And can you explain sort of what those types are and what the differences are or where they come from?
MR. ROBERTS: Sure. So there are multiple different types of alcohol, mainly based on the number of carbons that are within that molecule. You start off with methanol, which is one carbon — methanol you can find in like some rubbing alcohols, you can find them in many different labs, big large vials of them. Ethanol, which has two carbons — that one is the common one that is in our alcoholic beverages, and it goes all the way up — isopropanol, octanol, et cetera — it all depends on the number of carbons in the chain of it.
MR. LALLY: And the type that's reported within Miss Read's medical records — that was ethanol?
MR. ROBERTS: Correct.
MR. LALLY: And so with regard to your training and experience as a forensic toxicologist, are you familiar with a term known as a central nervous system depressant?
MR. ROBERTS: Yes.
MR. LALLY: And can you explain to the jury what that term means and how it relates to alcohol?
MR. ROBERTS: Sure. So alcohol is classified as a central nervous system depressant. Essentially the name kind of gives it away as to what it does. Your central nervous system is responsible for essentially all your movements, both involuntary and voluntary — so the way you move your head, the way you blink, the way you breathe, the central nervous system is responsible for all of that. With a depressant introduced into the body, it affects that central nervous system, causing things to slow down. So that's essentially what depressant means — it's going to slow down certain processes that the central nervous system would be in charge of. So you can have delayed reaction times, it can cause drowsiness.
MR. LALLY: How would that manifest as far as the central nervous system depressant affecting the body?
MS. LITTLE: Objection.
JUDGE CANNONE: I'm going to allow it.
MR. ROBERTS: There are many different effects that you could see, or side effects, from having a central nervous system depressant present in the body — lethargy, sleepiness, drowsiness, unable to walk properly, any one of those tests that you see on TV from the police when they try to get your horizontal gaze and they try to make sure you're coordinated — it can affect all those things.
MR. LALLY: Sir, are you also familiar through your training and experience working in forensic toxicology with a term known as retrograde extrapolation?
MR. ROBERTS: Yes.
MR. LALLY: And can you explain to the jury what you understand that term to mean?
MR. ROBERTS: So retrograde extrapolation is essentially another calculation, but it allows you to calculate what the possible blood alcohol content would have been at a time prior to when the blood was drawn. Say for instance blood was drawn at 2 — you could essentially figure out what the blood alcohol content would have been at 10 in the morning prior to it.
MR. LALLY: And that's done with a calculation as well — is that correct?
MR. ROBERTS: Yes.
MR. LALLY: Now what are some of the types of information that you would need to know, or that you would want to know, in order to perform a retrograde extrapolation?
MR. ROBERTS: We'd need to know, for sure, what the alcohol content would have been. We also need to know the time that the blood was drawn, as well as the time of the last alcohol consumption.
MR. LALLY: Now in regard to timing — what if any limitations are there in regard to performing retrograde extrapolation as it pertains to timing?
MR. ROBERTS: So when we do these calculations, anything that's shorter than two hours — we usually don't do that conversion.
MR. LALLY: And why is that?
MR. ROBERTS: Because we built in within our calculations we allow for two hours — and that has to do with the way that alcohol leaves the body. If the alcohol is still being absorbed by the body, we want to give it enough time to get to a point where it's coming out of the body as opposed to increasing in the body. So that two hours puts the person at a point in which that alcohol is coming out as opposed to it being absorbed.
MR. LALLY: So there are essentially three different sort of phases as far as intake of the alcohol into the body through dissipation, is that correct?
MR. ROBERTS: Yeah. We usually — there's a well-known kind of metabolism route to which alcohol metabolizes out of the body.
MR. LALLY: Yes. And so can you describe to the jury sort of that metabolism process, as far as how it starts to its end point?
MR. ROBERTS: Sure. So with having, let's say, one drink, what the body begins to do at that point is absorb the alcohol. Usually you get like a steady line that increases with time. So if you think of a regular chart where you have the level of alcohol in the body versus time — which would be on the Y axis, or sorry, the x-axis at the bottom — as time goes along, after your first drink the body starts to absorb the alcohol. If that was your only drink and that was it, the body then at a certain point stops absorbing it because there's no more to absorb and it plateaus. So essentially the line goes straight. After that point, the body starts to eliminate it. At this point the level, or your concentration of alcohol within the body, decreases with time as it's getting rid of it.
MR. LALLY: And so there's sort of the absorption phase, a plateau, and then the elimination phase, is that correct?
MR. ROBERTS: Yes.
MR. LALLY: Now, you mentioned that in the course of your analysis, where retrograde extrapolation is concerned, it's important to know sort of when the last drink was, is that right?
MR. ROBERTS: Yes.
MR. LALLY: And why is that?
MR. ROBERTS: That way we can get a good time in and figure out the amount of time that has passed between the last drink as well as the time that the blood was taken.
MR. LALLY: Now, did you perform a retrograde extrapolation analysis with regard to Miss Read's BAC, or the converted BAC from the serum conversion?
MR. ROBERTS: I did.
MR. LALLY: And so with reference to Miss Read, as far as you looked at the hospital records, you looked at the serum conversion report — what if anything else did you review or look at in coming to that retrograde extrapolation?
MR. ROBERTS: We usually get a police incident report, and that usually identifies a time — per their narrative — what time was the last drink.
MR. LALLY: May I approach the witness?
JUDGE CANNONE: Yes.
MR. LALLY: So again, presenting you with the document — if we can just look at that — Do you recognize that document, sir?
MR. ROBERTS: I do.
MR. LALLY: And what do you recognize it as?
MR. ROBERTS: This is the retrograde extrapolation report that I did for the subject of Karen Read.
MR. LALLY: Now with respect to the time that you utilized in that report — what was the time that you utilized as far as the last drink or time of operation?
MR. ROBERTS: The time that was utilized as the last drink was at 12:45, that'd be 12:45 a.m.
MR. LALLY: Is that correct?
MR. ROBERTS: Correct.
MR. LALLY: And so you're using that to sort of extrapolate from 9:08 a.m., when the 93 milligrams per deciliter is reported from Good Samaritan, to 12:45 a.m., correct?
MR. ROBERTS: Correct.
MR. LALLY: Now with regard to that 12:45 a.m., what if any difference would it make if it were a little bit off of that — say it was 12:30 a.m. or it was 1 or 1:10 a.m. — what if any impact would that have on your conversion?
MR. ROBERTS: So we tend to go by hours, so we kind of round to the nearest — I think — 15-minute interval. So a couple minutes or 10 to 20 minutes forward or behind of that 12:45, it wouldn't change the results by a lot, if any.
MR. LALLY: And similar to the serum conversion, is this done with different conversion factors as far as a low and average and a high?
MR. ROBERTS: So we usually just calculate a minimum and a maximum for the retrograde, and that incorporates some conversions as well.
MR. LALLY: Now as far as the minimum versus the maximum, what do each of those sort of signify or how do you come to those mathematical calculations?
MR. ROBERTS: So with the minimum calculation we incorporate the two-hour period, so we assume that maybe that 12:45 wasn't — the body wasn't at that point finished with the elimination, it wasn't in the elimination phase — so we allow it for two hours ahead of it. We also have a conversion factor. Once again, this is a study that was done to see the elimination rate of different people within a population — what rate they would get alcohol out of their system per hour. So we apply the lower limit, which was 0.1 g percent per hour, with that two-hour allotted time interval. And then we use the lower serum conversion number — the one that was converted on the lower end. We use all of that in the calculation in order to come up with the minimum.
MR. ROBERTS: The maximum one uses the opposite, so it uses the higher converted serum conversion number with the higher elimination rate using the full amount of time.
MR. LALLY: And these calculations, these conversion factors, are all based on sort of medical studies that you reviewed in literature that goes into your training?
MR. ROBERTS: Yeah, all of it was part of the training, and they came up with those numbers prior to even when I was there, but it is based on multiple different studies looking at that elimination rate.
MR. LALLY: And so from your calculations, when it came to the minimum with regard to the retrograde extrapolation — what if any result did you come up with from your calculations as it pertains to the minimum?
MR. ROBERTS: So the minimum amount that was calculated would have been 0.135 g percent.
MR. LALLY: And that's essentially reflected as a blood alcohol concentration, is that correct?
MR. ROBERTS: Correct.
MR. LALLY: And then with regard to the maximum — what if any result do you get from your mathematical calculations in regard to that?
MR. ROBERTS: The result was 0.292 g percent.
MR. LALLY: And so that range that you receive is a bit of a wide range, is that fair to say?
MR. ROBERTS: Yes.
MR. LALLY: And why is that?
MR. ROBERTS: So those calculations are based on that conversion that I did from the hospital results from serum, giving us a good range of values in the first place. But then we incorporate the retrograde extrapolation, which uses a time factor, and that two-hour difference using two different elimination rates causes a wider span of values. And it's just so that it can encompass essentially anybody within the general population — they would be somewhere in between that lower limit and that upper limit.
MR. LALLY: So essentially from those mathematical calculations, anyone within sort of the general population with that result would be somewhere between the 0.13 and the 0.29?
MR. ROBERTS: Correct.
MR. LALLY: May I approach?
JUDGE CANNONE: Yes.
MR. LALLY: One moment. Thank you, sir. I have no further questions.
JUDGE CANNONE: Okay. Little?
MS. LITTLE: Good afternoon.
MR. ROBERTS: Good afternoon.
MS. LITTLE: You used a method called retrograde extrapolation to reach your sort of opinions and conclusions in this case, correct?
MR. ROBERTS: Yeah, it was a calculation.
MS. LITTLE: And that means that you rely on an assumption that a trend will continue beyond sort of observable data?
MR. ROBERTS: So the metabolism is actually pretty well studied, so we know that that elimination rate — unless you introduce more alcohol into the system — it declines at that rate, and it's pretty linear.
MS. LITTLE: Exactly. So in other words, certain assumptions are incredibly important for you to reach your analysis?
MR. ROBERTS: Sure.
MS. LITTLE: And that includes sort of the timing of the very last drink that the individual had, is that right?
MR. ROBERTS: Yes.
MS. LITTLE: If your drinking pattern is sort of different than what you assume for purposes of your calculation, then you'd agree that your entire extrapolation would be incorrect, is that right?
MR. ROBERTS: Yes, it could be.
MS. LITTLE: And again, those assumptions sort of included the time of the incident, right?
MR. ROBERTS: Yes.
MS. LITTLE: And importantly, the time of the last drink?
MR. ROBERTS: Those two will be what we use — it's the time of the blood draw as well as the time of the incident or last drink.
MS. LITTLE: And your report acknowledges the testing that was used to obtain ethanol results in this case was not performed by the Massachusetts State Police crime lab, correct?
MR. ROBERTS: Correct.
MS. LITTLE: And for that reason, the report and those results do not fall under forensic lab accreditation standards, correct?
MR. ROBERTS: Correct.
MS. LITTLE: The Massachusetts State Police, as you testified, is an accredited forensic lab?
MR. ROBERTS: Yes.
MS. LITTLE: And so you're required to meet certain minimum standards in order to uphold that?
MR. ROBERTS: Yes.
MS. LITTLE: And you'd agree that those accreditation standards are different from accreditation standards that, say, a hospital lab might have?
MR. ROBERTS: They can be.
MS. LITTLE: And do you ever work on testing within the Massachusetts State Police lab for serum tests or whole blood tests?
MR. ROBERTS: So we did test blood and serum for alcohol content at the Massachusetts State Police crime lab.
MS. LITTLE: Yes. And their typical protocols are to use whole blood tests?
MR. ROBERTS: We use whole blood or serum.
MS. LITTLE: In terms of the machinery that's used with the Massachusetts State Police crime lab, you'd agree that the gold standard is gas chromatography and mass spectrometry machines?
JUDGE CANNONE: I'll let it go ahead. You can answer that.
MR. ROBERTS: Usually with a headspace detector, yes.
MS. LITTLE: And that would detect whole blood rather than serum?
MR. ROBERTS: No, it just detects any volatile substance.
MS. LITTLE: But you'd agree that a serum test, as you testified, has a much higher level than whole blood?
MR. ROBERTS: Yeah, due to the nature of the substance itself.
MS. LITTLE: And so you kind of have to go through this extra step of trying to extrapolate — how do I convert this to get to whole blood?
MR. ROBERTS: So what we incorporated, when anytime we ...had a blood — sorry, a serum sample submitted to the lab for alcohol testing. We actually did the same serum conversion in order to figure out what the blood alcohol concentration would have been.
MS. LITTLE: And that's an extra step that you have to take using conversion factors, correct?
MR. ROBERTS: Yep.
MS. LITTLE: Just the calculation — not actually testing for ethanol in the blood. You're testing via ADH, and then you have to do a conversion to get to what a whole blood test would just automatically show you.
MR. ROBERTS: Yeah. So we get the serum level and then we convert it via calculation.
MS. LITTLE: And typically in the Massachusetts State Police crime lab, you would do what's called confirmatory
MR. ROBERTS: Testing. Yeah, so we have a screening method as well as a confirmatory test.
MS. LITTLE: Correct. And confirmatory testing means that you take two separate samples and you test both of those?
MR. ROBERTS: Essentially — well, our protocol involved testing in duplicate. But that's not always the case. For the other drugs that we tested, we essentially have a screening test, which is one type of test, and then the confirmatory test would be a separate test, or sometimes even the same test just re-run the sample again.
MS. LITTLE: And the reason you typically would do two tests is to ensure that there's no error in the test, correct?
MR. ROBERTS: Um.
MS. LITTLE: And that acts as a fail-safe against false positives. And it also ensures that you're testing the correct sample, correct?
MR. ROBERTS: Correct.
MS. LITTLE: And in this case, obviously, you didn't conduct any of the testing, correct? You're just assuming the accuracy of a single test that was performed by the hospital.
JUDGE CANNONE: I'll allow it.
MR. ROBERTS: Yeah.
MS. LITTLE: And so if the clinical results are invalid, then your extrapolation is going to be invalid?
MR. ROBERTS: Yes.
MS. LITTLE: Now, we discussed a lot about serum testing and conversion rates. Do you recall that testimony?
MR. ROBERTS: Yeah.
MS. LITTLE: And you'd agree that the precise conversion rate between serum ethanol levels and whole blood ethanol levels is almost impossible to accurately predict for each individual person?
MR. ROBERTS: It would be difficult, yes.
MS. LITTLE: And that's because the amount of water in our blood is scientifically impossible to predict with accuracy?
MR. ROBERTS: I'm not aware of any kind of test that would do that, so yeah.
MS. LITTLE: Because individuals are different, right?
MR. ROBERTS: Yes.
MS. LITTLE: And so the conversions that you use are based on averages from scientific studies?
MR. ROBERTS: Yes.
MS. LITTLE: But you'd agree that in certain instances, people can fall outside of that average range?
MR. ROBERTS: Yeah.
MS. LITTLE: In fact, a comparison of hospital serum alcohol levels — they range quite wildly. You agree with that?
MR. ROBERTS: Yeah.
MS. LITTLE: In fact, you're aware that some studies show that a conversion rate from serum alcohol to blood alcohol can be as high as 1.59?
MR. ROBERTS: I wasn't aware of those numbers, but yeah, it could range. That's why we give a wide range.
MS. LITTLE: And you could fall on the outskirts of either side. And so that would mean that the actual blood alcohol content, once it goes through the conversion rate, would be much, much lower than the average conversion rate that you relied on?
MR. ROBERTS: Yeah, it could be both higher and lower.
MS. LITTLE: And that includes within that range that you gave, right?
MR. ROBERTS: Yeah, it could fall within the range.
MS. LITTLE: You'd agree that the more imprecise an extrapolation is, the less reliable it is?
MR. ROBERTS: Yeah, you do have to base it on good — your starting blocks have to be good. So you have to know the times in which the blood was drawn, the time of the incident, and essentially what your value was for your BAC — and the time of the last drink. You'd want to know that. So we would put that around the time — yeah, either the time of the last drink or the incident date.
MS. LITTLE: And so the more unknowns you're trying to account for, you'd agree the less reliable your end result is going to be?
MR. ROBERTS: It could be, yes.
MS. LITTLE: And you'd agree that the range you gave in this case — which was 0.135 to 0.292 — that's a very, very large disparity?
MR. ROBERTS: Yeah, almost a sort of 120% swing.
MS. LITTLE: Yeah. That would be the equivalent of, for example, predicting a child's going to grow somewhere from 6 feet to 14 feet.
MR. LALLY: Objection.
JUDGE CANNONE: Sustained.
MS. LITTLE: It's a very large number. You'd agree with that?
MR. ROBERTS: Yeah, there's a large range. Like I said, due to the factors involved in the calculation, that's how it gets so large.
MS. LITTLE: And that's because you're working with a lot of unknowns in this case?
MR. ROBERTS: Yes.
MS. LITTLE: Now, you testified that retrograde extrapolation assumes that Miss Read reached the elimination phase of processing alcohol at or before 12:45 a.m.?
MR. ROBERTS: Yeah, we allow for — we start for the maximum at 12:45, and then it would have been 2:45 for the minimum.
MS. LITTLE: And so for purposes of your calculation, if Miss Read drank alcohol after 12:45 a.m. and before her blood was drawn at 9:08 a.m., your entire calculation would be invalid?
MR. ROBERTS: Uh, yeah.
MS. LITTLE: No further questions.
JUDGE CANNONE: Okay, Mr. Lally?
MR. LALLY: Just briefly, please.
MR. LALLY: So in this instance, Mr. Roberts, you're dealing with the time of incident — that was known, correct?
MR. ROBERTS: Yes, it was. It was given to me that it was at 12:45. And as far as the BAC — or the serum conversion — that was coming from a medical record. So that was known as well, at 9:08 in the morning, the time that the blood was drawn.
MR. LALLY: Yeah, that was known as well. Now, as far as the question you were just asked — if the defendant drank alcohol after 12:45 — does that include sort of shortly after 12:45, or how long after 12:45 would it take in order to affect your calculations or your retrograde extrapolation?
MR. ROBERTS: It's hard to say where that would have skewed it. It would have definitely caused a different time frame depending on how long after the incident or the reported last drink. If there was another drink in between, it would shorten up the amount of time that would have been prior to the blood draw for sure.
MR. LALLY: What I'm asking is, would it have any significant impact? Would there be any difference if the last drink was, say, at 1:00 a.m. versus 5:00 a.m.? So that would be a 4-hour
MR. ROBERTS: Difference. So essentially that could — that could, given the conversion rates — that would put the numbers very different.
MR. LALLY: Yeah. But what I'm saying is, the 5:00 a.m. would significantly impact your calculations, correct?
MR. ROBERTS: Yes.
MR. LALLY: 1:00 a.m. — would that significantly impact your calculations?
MR. ROBERTS: No.
JUDGE CANNONE: You all set, Miss Little?
MS. LITTLE: I could just ask one question. You said that you were given 12:45 as the time that you based your analysis on, and clearly that was not something that was provided to you by my client, right?
MR. ROBERTS: No.
MS. LITTLE: That was something that was provided to you from a police report, correct? No further questions.
JUDGE CANNONE: Okay. All right, Mr. Roberts, you are all set, sir.
MR. ROBERTS: Thank you very much.