Commonwealth v. Read — Trial ArchiveNicholas Roberts — Direct/Cross/Redirect/Recross
339 linesWhereupon, NICHOLAS ROBERTS having been first duly sworn, was examined and testified under oath as follows:
JUDGE CANNONE: All right, Mr. Lally.
MR. LALLY: Thank you, Your Honor.
DIRECT EXAMINATION BY MR. LALLY:
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: Sir, 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 or 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 lab for 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 Degree in Applied Forensic Science with a concentration in Chemistry and Toxicology from Mercyhurst University. That's in Erie, Pennsylvania. 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 from there?
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 at the Mass. State Police Crime Lab.
MR. LALLY: Now, when you were initially hired at the Mass. State Police Crime Lab, you were working initially as a Forensic Scientist I; 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 I?
MR. ROBERTS: So as a Forensic Scientist I, you're essentially going through all the trainings that they provide at the lab. We do a number of different tests mainly on blood and urine, looking for the presence of drugs and alcohol. We also do serum conversions and retrogrades. So during your training period, I started as an FSI. So that went up until I was fully signed off to actually write reports that would be issued to A.D.A.s across Massachusetts and which I became a Forensic Scientist II.
MR. LALLY: And so what is the difference, sir, between sort of your work as a Forensic Scientist I versus your work as a Forensic Scientist II?
MR. ROBERTS: So essentially as a two-year, essentially 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 an Forensic Scientist I, you're still in that training process.
MR. LALLY: And did you work essentially as a Forensic Scientist II from that point in time until the time that you left the lab in November of '23?
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. We would habitually receive articles based on different discoveries within the forensic field. So 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 or solicited on the street, et cetera, et cetera. We would often get different articles, just research papers, based on what they are 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, what, if any, sort of -- are you familiar with the term "proficiency testing"?
MR. ROBERTS: Yes.
MR. LALLY: And 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 is we would have internal people sending us samples as if it came from an external source. And then the external proficiency testing I receive is actually part of our accreditation. So it came in just like regular samples, and we are tested accordingly per our 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 a national 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 an 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 through an external entity; is that correct?
MR. ROBERTS: Yes.
MR. LALLY: Now, with regard to the lab as far as your assignment of work, at the time that you left the lab, about how many Forensic Scientists II's were working within the lab in your toxicology unit?
MR. ROBERTS: By the time that I left?
MR. LALLY: Yes.
MR. ROBERTS: 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 Scientists II's at the time that you worked at the lab, was there some sort of rotation or how were you assigned work as it related to your work in the toxicology unit?
MR. ROBERTS: So throughout my time there, we had more Forensic Scientists I's and II's and we would delegate each type of assignments that we would look for, the different types of testing. On a monthly basis, we would get a different group of tests that we performed 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: And 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 Ms. 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 and what is it that you're reviewing or you're looking at? How is a serum conversion -- what is it and how is it 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 A.D.A.s or get results from the hospitals that whoever was attended to, we get the results. And usually hospital alcohol results, they 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 the heavier materials out of that blood. And what's left is the serum. So they use that to test their alcohol. What studies have shown is that they actually tend to have a higher alcohol concentration in serum than in blood. So that means that due to the chemical nature of alcohol, it likes to stay in that liquid portion more than throughout the whole blood. So a 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 Ms. Read's medical records?
MR. LALLY: Your Honor, may I approach the witness?
JUDGE CANNONE: Yes.
BY MR. LALLY:
MR. LALLY: Sir, I'm showing you a document. I'd just ask you to review that and look up when you're finished.
MR. ROBERTS: (Witness complies.)
MR. LALLY: Do you recognize that, sir?
MR. ROBERTS: Yes.
MR. LALLY: And what do you recognize that to be?
MR. ROBERTS: So this is the serum conversion report that I made or the calculations were made on May 3rd of 2022.
MR. LALLY: And, as far as the result that you received in addition -- so what kind of materials did you receive in order to perform that analysis?
MR. ROBERTS: We got the medical records.
MR. LALLY: May I approach the witness again, Your Honor?
JUDGE CANNONE: Yes.
BY MR. LALLY:
MR. LALLY: Sir, I'm going to show you what's been marked as Exhibit 106 and directing your attention to this last page contained within this document here. Is that a portion of the medical records that you reviewed in regard to Ms. Read's serum alcohol level?
MR. ROBERTS: Yes.
MR. LALLY: And, if you could, what was reported in the medical records that you reviewed and using 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 the records?
MR. ROBERTS: Yes.
MR. LALLY: And what was that time, sir?
MR. ROBERTS: It was at 9:00 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 what you did in relation to that?
MR. ROBERTS: What do you mean?
MR. LALLY: Let me -- that was very poorly phrased. Let me try to restate that a better way. What is your understanding of forensic science and can you explain that to the jury?
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: And 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 your understanding -- based on your training and experience, what is forensic toxicology?
MR. ROBERTS: So toxicology in general is generally just the study of poisons, plainly speaking. So anything that would be harmful to the body essentially, that would be toxicology because we also not only have forensic toxicology, but you also have like environmental. And the forensic toxicology is just, like I said again, with the forensic science, is just basing it on things for legal purposes.
MR. LALLY: Now, through your training and experience, are you familiar with sort of 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 serum plasma is what it's called. It can be referred to as either/or or one or the other. So that is 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 as 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 Ms. 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: Yes. From my experience in all the times that I've seen serum conversions come to the lab, milligrams per deciliter are the units that they use from the hospital. Yeah.
MR. LALLY: Now, as far as that 93 milligrams per deciliter, what, if anything, 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 are able to apply different conversion factors to the numbers that we would get in serum and we usually get -- excuse me. We usually give a low, an average anda high being that it's kind of hard to say what one particular person's conversion factor would be between the two of them since it's dependent upon like age, sex, the water content, what you had to eat that day. So it's harder to pinpoint. Therefore, we give a good range as what it could possibly be, pertaining just -- just in case a person converts or their conversion would be a lot lower or higher. So we give a good range.
MR. LALLY: And, as far as those different conversion factors, where do those come from?
MR. ROBERTS: That's based on some studies. I don't remember the actual names of the papers, but they were 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 are 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 a centrifuge, what, if any, relationship does that have to the reading that you get or the conversion factors that you're using?
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, more essentially the lower the concentration could be of that, 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 conversion factors?
MR. ROBERTS: So the low is a 1.18 with the average being a 1.14 and then the high being a 1.12.
MR. LALLY: So based on your analysis as far as the medical records and what was reported to you, using those three conversion factors, what, if anything, did you come up with as far as the low, an average anda high for the 93 milligrams per deciliter?
MR. ROBERTS: So our values that were calculated for the low was a 0.078 gram percent. The high was a 0.083 gram percent with the average being a 0.081.
MR. LALLY: Now, sir, with reference to the alcohol that's recorded 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 the difference -- 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. You have big, large vials of them. Ethanol, which has two carbons. That one is the common one that is in our alcohol 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 Ms. Read's medical records, that was ethanol, correct?
MR. ROBERTS: Correct.
MR. LALLY: And so with regard to your training and experience as a forensic toxicologist, are you familiar with the 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 what 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 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.
MS. LITTLE: Objection.
JUDGE CANNONE: Ask another question.
MR. LALLY: Sure.
BY MR. LALLY:
MR. LALLY: How would that manifest as far as a central nervous depressant affecting the body?
MR. LALLY: Objection.
JUDGE CANNONE: Overruled.
by Mr. Lally
MR. LALLY: Go ahead, sir.
MR. ROBERTS: There are many different effects that you can see or side effects from having a central nervous system depressant in the body: lethargy, sleepiness, drowsiness, unable to walk properly. Any kind of -- any one of those tests that you see on T.V. from the police when they try to get your horizontal gaze and they try to make sure that you're coordinated. It can affect all those things.
MR. LALLY: Now, sir, are you also familiar through your training and experience and work in 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 a retrograde extrapolation is essentially another calculation. But it allows you to be able 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 2:00, you could essentially figure out what the blood alcohol content would have been at 10:00 in the morning prior to it.
MR. LALLY: And that's done with the 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 would need to know, one, 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 as far as what, if any limitations are there in regard to perform retrograde extrapolation as it pertains to timing is concerned?
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, sir?
MR. ROBERTS: Because built in within our calculations, we allow for two hours. 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 put the person at a point in which that alcohol would be 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. There is a well-known kind of metabolism route to which the alcohol metabolizes out of the body. Yes.
MR. LALLY: And so can you describe to the jury sort of that metabolism process as far as how it starts to its ending?
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 level 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 of 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 is 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. And then your 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 in the course of your analysis for retrograde extrapolation, it's important to know sort of when the last drink was; is that right?
MR. ROBERTS: Yes.
MR. LALLY: And why is it?
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 Ms. Read's BAC or the converted BAC from the serum conversion?
MR. ROBERTS: I did.
MR. LALLY: And so with reference to Ms. Read as far as you looked at obviously 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 analysis?
MR. ROBERTS: We usually get a police incident report, and that usually identifies the time at which further narrative, what time they had their last drink.
MR. LALLY: May I approach the witness, Your Honor?
JUDGE CANNONE: Yes.
BY MR. LALLY:
MR. LALLY: Sir, I again present you with a document. If you could just look at that and look up when you're finished.
MR. ROBERTS: (Witness complies.)
MR. LALLY: Do you recognize that document, sir?
MR. ROBERTS: I do.
MR. LALLY: And what do you recognize it to be?
MR. ROBERTS: This is the retrograde extrapolation report I did for the subject of Karen Read.
MR. LALLY: Now, with respect to the time that you utilize in that report as far as -- when was the time that's utilized as far as the last drink or time of operation?
MR. ROBERTS: The time that was utilized as the last drink, it was at 12:45.
MR. LALLY: And that would be 12:45 a.m.; 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 milligram 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 1:00 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, 50-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, an average and a high?
MR. ROBERTS: So we usually just calculate a minimum anda 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 a 0.1 gram 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. 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 or 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 hired there. But it is based on multiple different studies in that, 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, calculation, what, if any, result did you come from with your calculations as it pertained to the minimum?
MR. ROBERTS: So the minimum amount that was calculated would have been a 0.125 gram percent.
MR. LALLY: And that's essentially reporting in a blood alcohol concentration; is that correct?
MR. ROBERTS: Correct.
MR. LALLY: And then with regard to the maximum, what, if any, result did you get from your mathematical calculations in regard to that?
MR. ROBERTS: The result was a 0.292 gram 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, sir?
MR. ROBERTS: So we based those calculations, they are based on that conversion that I did from the hospital results from serum, giving us two -- giving us a good range of values in the first place. But then we incorporate the retrograde extrapolation one which uses a time factor. And that two-hour difference, using two different elimination rates, that causes a wider span of values. And it's just so that it can encompass essentially anybody within the general population that 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 .13 and the .29, correct?
MR. ROBERTS: Correct.
MR. LALLY: May I approach just to retrieve, Your Honor?
JUDGE CANNONE: Yes.
MR. LALLY: If I could have one moment, Your Honor?
JUDGE CANNONE: Yes.
MR. LALLY: Thank you, sir. I have no further questions.
JUDGE CANNONE: Ms. Little?
MS. LITTLE: Thank you.
CROSS-EXAMINATION BY MS. 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: Extremely. 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: So those two will be what we use, is 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?
MR. ROBERTS: Correct.
MS. LITTLE: And, for that reason, the report and those results do not fall under your forensic lab accreditation standards?
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 accreditations 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 the blood and serum for alcohol content at the Massachusetts State Police Crime Lab, yes.
MS. LITTLE: 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?
MR. ROBERTS: Usually with a head space detector.
MR. LALLY: Objection.
JUDGE CANNONE: I am going to -- go ahead. You can answer that.
MR. ROBERTS: Usually with a head space detector, yes.
BY MS. LITTLE:
MS. LITTLE: And that would detect whole blood rather than serum?
MR. ROBERTS: No. It detects any volatile substance.
MS. LITTLE: But you'd agree that a serum test, usually, as you testified, has as 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, okay, how do I convert this to get to whole blood?
MR. ROBERTS: So what we incorporated any time 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: Yes, as a calculation.
MS. LITTLE: You're not actually testing for ethanol in the blood. You're testing for NADH. And then you have to do a conversion to get it to what a whole blood test just automatically would show you?
MR. ROBERTS: Yes. So we get the serum level. And then we convert it by a calculation.
MS. LITTLE: And typically in the Massachusetts State Police Crime Lab, you would do what's called confirmatory testing; is that right?
MR. ROBERTS: Yes. So we have a screening method as well as a confirmatory test. Correct.
MS. LITTLE: 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 screen test, which is one type of test. And then the confirmatory test would be a separate test or sometimes even the same test, just rerun the sample again.
MS. LITTLE: And the reason you typically would do two tests is to ensure that there is no error in the testing?
MR. ROBERTS: Correct.
MS. LITTLE: And that acts as a failsafe against false positives. You'd agree with that?
MR. ROBERTS: Yes.
MS. LITTLE: And it also ensures that you're testing the correct sample?
MR. ROBERTS: Correct.
MS. LITTLE: And, in this case, obviously, you didn't conduct any of the testing?
MR. ROBERTS: Correct.
MS. LITTLE: You're just assuming the accuracy of a single test that was performed by a hospital?
MR. LALLY: Objection.
JUDGE CANNONE: I'll allow it.
MR. ROBERTS: Yes.
BY MS. LITTLE:
MS. LITTLE: And so if the clinical results are invalid, then your extrapolation is going to be invalid?
MR. ROBERTS: Yes.
MS. LITTLE: Now, you discussed a lot about sort of 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?
MR. ROBERTS: For each individual person, 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, you know, hospital serum alcohol levels, they range quite wildly. You'd 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 percent?
MR. ROBERTS: I wasn't aware of those numbers, but yeah. It could range -- that's why we give a wide range, and you could lie on the outskirts of either side.
MS. LITTLE: And so that would mean that the actual blood alcohol content, once it goes through the conversion rate, would be much, much lower than sort of the average conversion rate that you relied on?
MR. ROBERTS: Yeah. It could be both higher and lower.
MS. LITTLE: And that includes that range that you gave, right?
MR. ROBERTS: Yeah. It could fall into either 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.
MS. LITTLE: And the time of the last drink? You'd want to know that?
MR. ROBERTS: 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 sort of 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 sort of the range you gave in this case, which was .135 to .292, that's a very, very large disparity?
MR. ROBERTS: Yeah.
MS. LITTLE: Almost sort of a 120-percent swing?
MR. ROBERTS: Yeah.
MS. LITTLE: That would be the equivalent, for example, predicting a child is going to grow somewhere from six feet to 14 feet?
MR. LALLY: Objection.
JUDGE CANNONE: Sustained.
BY MS. LITTLE:
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 acting with a lot of unknowns in this case?
MR. ROBERTS: Yes.
MS. LITTLE: Now, you testified that your retrograde extrapolation assumes that Ms. Read reached the elimination phase of processing alcohol at or before sort of 12:45 a.m.?
MR. ROBERTS: Yeah. We start for the maximum at the 12:45. And then it would have been 2:45 for the minimum.
MS. LITTLE: And so for purposes of your calculation, if Ms. 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: Yeah.
MS. LITTLE: No further questions.
JUDGE CANNONE: Anything, Mr. Lally?
MR. LALLY: Just briefly.
REDIRECT EXAMINATION BY MR. LALLY:
MR. LALLY: So in this instance, Mr. Roberts, you're dealing with a time of incident that was known, correct?
MR. ROBERTS: Yes. It was given to me that it was at 12:45.
MR. LALLY: And, as far as the BAC or the serum conversion that was coming from a medical record as far as so that was known as well at 9:08 in the morning?
MR. ROBERTS: The time that the blood was drawn. Yeah. That was known, as well.
MR. LALLY: 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 there. It would shorten up the amount of time that would have been prior to the blood draw, for sure.
MR. LALLY: So what I'm asking you is would it have any Significant impact or would there be any difference if the last drink was, say, at 1:00 a.m. versus 5:00 a.m.?
MR. ROBERTS: So that would be a four-hour difference.
MR. LALLY: Right.
MR. ROBERTS: So essentially, that could -- given the conversion rates, that would be -- that would put the numbers very different. Yeah.
MR. LALLY: Well, what I'm saying is so the 5:00 a.m. would significantly impact your calculations, correct?
MR. ROBERTS: Yes.
MR. LALLY: The 1:00 a.m., would that significantly impact your calculations?
MR. ROBERTS: No.
MR. LALLY: Nothing further.
JUDGE CANNONE: Are you all set, Ms. Little?
MS. LITTLE: If I could just ask one question.
JUDGE CANNONE: Sure.
RECROSS-EXAMINATION BY MS. LITTLE:
MS. LITTLE: You said that you were given 12:45 as the time that you sort of based your analysis on?
MR. ROBERTS: Yes.
MS. LITTLE: And, to be clear, 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?
MR. ROBERTS: Correct.
MS. LITTLE: No further questions.
JUDGE CANNONE: All right. Mr. Roberts, you are all set, sir. Thank you very much.
(Whereupon, the witness was excused.)
JUDGE CANNONE: Your next witness, Mr. Lally?
MR. LALLY: Yes, Your Honor. The Commonwealth calls Mr. Michael Trotta to the stand.