Opinion ID: 1989907
Heading Depth: 3
Heading Rank: 4

Heading: Acceptable Tolerance Analysis

Text: The Special Master recommended that the firmware be revised to correct the acceptable tolerance among the reported results so as to permit results to be accepted if they are within plus or minus 0.005 percent BAC or plus or minus five percent of the mean for the four readings, whichever is greater. (Special Master's Finding 10). Although the State does not dispute the need to correct future firmware versions, both the recommendation of the Special Master as to the acceptable tolerance range and the effect of this determination upon pending cases require our analysis. The acceptable tolerance question raises a variety of concerns, including its implications for the validity of any particular test result, our confidence in the accuracy and reliability of a specific Alcotest unit, the need for performance of a third test on any particular test subject, and the appropriate method by which to assess tolerance in light of changes to the quantification of the per se violation in recent years. We address each of these difficult issues in turn.
Tolerance is the range of any set of measurements that is accepted as being representative of a true reading. Precision and accuracy can be ensured by requiring the application of a narrow range for tolerance. Conversely, the wider the acceptable tolerance between reported results, the lower our confidence in the accuracy of any of the reported results. Therefore, for purposes of permitting any device to be utilized for proof of a per se violation of the statute, the acceptable tolerance is of fundamental importance. As a matter of historical perspective, we first considered the question of acceptable tolerance ranges in Romano, supra . There, as a part of our evaluation of whether the test results obtained from two breathalyzer models which might have been affected by radio frequency interference (RFI) could be admissible, we accepted the 0.01 percent BAC standard as a scientifically reliable tolerance range, based on the opinions of two experts who so opined, see Romano, supra, 96 N.J. at 86, 474 A. 2d 1. At the time, the statute created a per se offense for any person whose BAC was 0.10 percent or greater, see id. at 78, 474 A. 2d 1. As we articulated the tolerance analysis in Romano, admissibility is satisfactorily established . . . [i]f the breathalyzer results consist of two tests or readings within a tolerance of 0.01 percent of each other. . . . Id. at 87-88, 474 A. 2d 1. The point, of course, was that if a breathalyzer that might be influenced by RFI could nevertheless read two separate breath samples with results within this range, we would presume those results were unaffected by external influences and, therefore, valid. After our decision in Romano, the 0.01 percent BAC tolerance range became the benchmark against which all breathalyzer results, not just those from RFI-susceptible models, were tested for general reliability and accuracy. In Downie, we again referred to the 0.01 percent BAC tolerance range as a benchmark for reporting accurate results. See Downie, supra, 117 N.J. at 455, 569 A. 2d 242. Although we did not independently evaluate the continuing validity of that tolerance range, we adhered to it as a part of our evaluation of the overall scientific accuracy and reliability of the breathalyzer. Indeed, we have never departed from that standard and have not previously been called upon to consider any different articulation of that accepted range of tolerance. Prior to the trial court's decision in Foley, the tolerance range for the Alcotest was fixed by the software to be 0.01 percent BAC or a range of ten percent for all samples. That range was determined by Brettell when the Alcotest program was first devised. The range, however, was tested by reference to the arithmetic mean, the effect of which halves the expression of the range. In addressing the challenge to the tolerance as being inconsistent with Romano, the court in Foley described the tolerance as fixed in the Alcotest in somewhat different terms. The Foley court explained that our long-accepted standard of a required tolerance of 0.01 percent BAC between two breath samples was the strictest standard in the United States, and concluded that, as applied to the four results derived by Alcotest, the additional parameter of ±10 [percent] is within the tolerance considered acceptable for reliable results by the scientific community. Foley, supra, 370 N.J.Super. at 357, 851 A. 2d 123. In so articulating the tolerance range, however, the court did not simply re-articulate a long-accepted tolerance, expressing it as a percentage rather than an absolute. Nor did it accurately express the tolerance used by the device, an earlier version of software known as Firmware version 3.8, in which the tolerance was expressed in alternate terms. Rather, the court, inadvertently, we think, endorsed a tolerance range that effectively doubled that which we have allowed. There are several considerations arising from this expanded tolerance that are now before us. First, the use of a percentage tolerance range tends to permit readings at higher levels that are wide of the previously accepted 0.01 percent BAC standard. This might lead to results that are, in and of themselves suspicious in terms of their intrinsic reliability. That is to say, although for purposes of guilt, it might not matter whether we accepted two test results that were within ten percent but beyond 0.01 percent BAC of each other, those results might raise a concern about the overall reliability of the particular machine. Second, however, use of an absolute rather than a percentage might arguably disadvantage subjects whose test results are at the lower end of the range by accepting test results that are, by percentage, more widely separated and that would be rejected as out of tolerance were a percentage analysis applied. Third, in some measure the amendments to the statute and the creation of new per se offenses, not extant when we considered the acceptable tolerance in Romano and Downie, makes our evaluation of this issue more complex. In the abstract, tested against a statute that only utilized one per se test for drunkenness, namely, 0.10 percent BAC, our acceptance of the single test for acceptable tolerance was well supported in the scientific record. The question, in light of the lowered per se limits now in force, is what we should demand in terms of precision to demonstrate accuracy and support admissibility. Taking into account these considerations, we turn to an evaluation of the evidence in the record concerning tolerance and its significance. At present, assuming the subject has provided an otherwise acceptable sample, the Alcotest reports the EC and IR results of the first sample. The device is programmed to accept the EC and IR test results from a second sample only if those results are within its programmed tolerance of the EC and IR results from the first breath sample. If the second-sample results are not within the tolerance, the Alcotest will record the results, but require a third sample. For Firmware version 3.8, used in the Alcotest program at issue in Foley, Brettell testified that he set the tolerance in accordance with the breathalyzer tolerance expressed in Downie. He interpreted the Downie standard to mean that two breath tests had to be within 0.01 percent BAC of each other when the mean BAC measured below 0.10 percent BAC, which was the per se level when Downie was decided. Brettell testified that, notwithstanding the fact that the Court never varied from the 0.01 percent BAC standard, he assumed we intended a tolerance of ten percent for BAC values above 0.10 percent BAC. Therefore, Firmware version 3.8 was programmed to accept the second breath test if there was no more than 0.01 percent BAC or ten percent between the highest and lowest readings. Notwithstanding Brettell's acknowledgment that he knew that the Foley statement about tolerance was mathematically incorrect, he concedes that following the decision in Foley, the State directed Draeger to reprogram the device so as to take advantage of that far wider, effectively doubled, range for tolerance. He explained that he did so to make the test conform with programs in other states and to address criticism of the relative frequency with which the device in Foley rejected results for being out of tolerance and required the administration of a third test. Brettell believed that taking advantage of the court-sanctioned wider tolerance would alleviate a similar challenge in the future. The State concedes that Firmware version 3.11 did precisely that, creating a range of either plus ten percent or minus ten percent of the mean, for a doubled tolerance. [28]
Although New Jersey, prior to the introduction of Firmware version 3.11, in compliance with our decision in Romano and Downie, adhered to the 0.01 percent BAC tolerance standard, there is no general agreement among the states as to what standard is acceptable. Many states other than New Jersey utilize the 0.01 percent BAC tolerance standard as well, but the National Safety Council, for example, recommends a tolerance of no more than 0.02 between the highest and lowest readings. One of the State's witnesses, Rod Gullberg, testified about his previously published conclusions on tolerance measurement. He opined, therefore, that the Firmware version 3.11 tolerance is too broad. See R.G. Gullberg, Determining an Appropriate Standard for Duplicate Breath Test Agreement, 39 Can. Soc'y Forensic Sci. J. 15, 23 (2006). Instead, he recommended using plus or minus five percent of the mean of the four tests. He estimated that if the firmware were changed to utilize this tolerance, the number of people who would have to submit additional samples would increase by approximately five percent. That estimate is mirrored by a comparison of the data from Pennsauken, in which Firmware version 3.8 was used, with the data from Middlesex County, in which Firmware version 3.11, with its doubled tolerance, was used. Another of the State's witnesses, Hansueli Ryser, explained that if New Jersey used a tolerance of plus or minus 0.005 percent BAC, or plus or minus five percent, of the mean, whichever is greater, then for mean measurements below 0.10 percent BAC, the acceptable tolerance would be plus or minus 0.005 percent BAC. As an example, if a person had a mean alcohol concentration of 0.08 percent BAC, the tests would be in tolerance if they fell between 0.075 and 0.085 percent BAC. [29] For mean concentrations above 0.10 percent BAC, the relevant tolerance would be plus or minus five percent. Brettell testified that he planned to revisit the tolerance because it had caused so much litigation. He testified that the 0.02 percent BAC National Safety Council recommendation might be the easiest to adopt, but he preferred the use of a combination of a set value and a percentage because the percentage would account for scientifically defensible wider tolerance at very high values. Overall he favored [30] plus or minus 0.005 percent BAC from the mean or plus or minus five percent of the mean, whichever was greater.
Although we have never considered the use of a tolerance other than the absolute 0.01 authorized in Romano, intervening legislative enactments require us to address the continuing validity of that standard. At the time that we decided the question of acceptable tolerance in Romano, there was but one per se standard for drunk driving prosecutions, namely, the 0.10 percent BAC. Since that time, however, the Legislature has reduced that per se limit to 0.08 percent BAC, while maintaining the 0.10 percent BAC standard for enhanced punishment. [31] The issue is what measure of tolerance comports with scientifically reliable, and therefore admissible, results. Expressing the tolerance in terms of the greater of the absolute or a percentage of deviation from the mean authorizes, in effect, a wider range of tolerance at the higher readings. There is, in this record, evidence that demonstrates to our satisfaction that at the higher readings, all measures of BAC are somewhat less precise than they are at the lower ranges. As a result, the wider tolerance expressed by a percentage deviation from the mean applied to the upper ranges of possible readings does not suggest that the device is not working properly. At the lower readings, in contrast, a deviation outside of the tolerance limit we have traditionally required most assuredly will raise a question about the functioning of the particular device. Our evaluation of the record compels us to conclude that, even in light of the lowered overall per se limit adopted since Romano, the continued use of the absolute 0.01 percent BAC standard, coupled with the use of a like range of tolerance expressed as a percentage deviation from the mean, is both scientifically appropriate and consistent with our understanding of the intention of the Legislature in adopting these per se limits. To the extent that Firmware version 3.11 took advantage of an explanation of the tolerance range in Foley that inadvertently doubled the permissible range, however, it cannot be sustained. We therefore direct that for future firmware revisions, the device be programmed to fix the tolerance range to be plus or minus 0.005 percent BAC from the mean or plus or minus five percent of the mean, whichever is greater, in order to ensure scientifically accurate, admissible test results.
Our inquiry, however, cannot end there. There is stark evidence in the record, based on a comparison of the data from the Pennsauken program, in which the device with Firmware version 3.8 and the appropriate tolerance was utilized, with the data collected in Middlesex County, using Firmware version 3.11 and its doubled range, that the intervening expansion of the tolerance range resulted in tests being deemed acceptable by the device that cannot meet the tolerance range we have required. In fact, the data demonstrates that precisely the effect that Brettell desired, namely, reducing the frequency of out of tolerance readings that required third samples, was achieved to the point of apparent elimination. The Special Master, while recommending that the software be revised for future uses to reflect his analysis of acceptable tolerance ranges, did not regard the State's adoption of a different and widely expanded tolerance to be problematical for pending prosecutions. The State urges us to adopt this finding that the doubled tolerance had no effect on any defendant's substantive rights. We disagree. The simple fact is that the tolerance range is a critical component in our conclusion that this or any other device correctly and accurately measures breath alcohol and converts that data into a scientifically reliable, accurate BAC analysis. Our acceptance of those results for purposes of supporting, without more, a criminal conviction, must be based on our conclusion that the results are reliable and accurate. The use of a doubled tolerance, however, deprived some percentage of test subjects of a third, and perhaps dispositive, test. At the same time, it undermines our confidence in the accuracy of the reports of those tests that fall outside of the range that we have demanded be utilized as a prerequisite for scientific accuracy and that undergirds admissibility in a criminal proceeding. It is easy enough to identify those individuals for whom a third test should have been given. To be sure, if we had the third test data for those defendants, some of them would achieve a result within the authorized tolerance and thus be shown to have violated the per se limits. But just as surely, there may be others for whom a third test would have yielded a result still further out of range so as to, perhaps, call the accuracy of the particular machine into question. And it is even possible that there might be a defendant for whom a third test would result in a reading that would meet the test for tolerance but would exonerate that individual. The suggestion that we permit those test results that are outside of the range for tolerance to be utilized for purposes of a per se conviction unfortunately is, simply put, unacceptable. Zealousness in ridding our roads of drunk drivers cannot overcome our ordinary notions of fairness to those accused of these offenses. Therefore, we are constrained to direct not only that future firmware updates utilize the tolerance computation that we have concluded is acceptable, but that all pending prosecutions include an evaluation of whether the two reported test results exceeded this acceptable tolerance. Any AIR that reports results from tests of only two breath samples, therefore, must be analyzed to determine whether its results are within our accepted tolerance by use of a mathematical calculation. The appropriate calculation for this purpose will consist of applying the following formula: (a) add the IR and EC results given for the first breath sample to the IR and EC results for the second breath sample; (b) divide the sum calculated in (a) by 4 to derive the arithmetic mean; (c) compute the upper limit of tolerance by taking the larger value of the mean multiplied by 1.05 or the mean plus 0.005 percent BAC; (d) compute the lower limit of tolerance by taking the smaller of the value of the mean multiplied by 0.95 or the mean minus 0.005 percent BAC; (e) if all of the IR and EC results of the two samples fall within the upper and lower limits of the tolerance range, the AIR is valid, but if any of the results fall outside of the tolerance range, the AIR is not valid. Although we have prepared a worksheet that is attached to the order that accompanies this opinion for use in all prosecutions pending reprogramming of the device, two examples will, we think, illustrate the way in which the formula should be utilized in practice to differentiate between an AIR that reports results within tolerance and one that does not. If, for example, a defendant's first breath test sample yielded an IR result of 0.100 percent BAC and an EC result of 0.101 percent BAC, and the second sample yielded an IR result of 0.104 percent BAC and an EC result of 0.103 percent BAC, the calculations would be performed as follows: (a) first all four of the results (two IR and two EC) would be added, in this example, 0.100 + 0.101 + 0.104 + 0.103 = 0.408; (b) next, the arithmetic mean would be derived by dividing that sum by four, 0.408 / 4 = 0.102; (c) then the upper limit of acceptable tolerance must be determined by comparing the two methods for computing the range, namely, the use of the absolute or the percentage. This is done by computing each separately and selecting the greater of the two. In this example, the computation would yield the following options: (0.102 x 1.05 = 0.1071) OR (0.102 + 0.005 = 0.1070). Because the greater of these is 0.1071, that will be the correct upper tolerance limit; (d) next, the lower limit of acceptable tolerance must be derived by comparing the two methods for computing the range, again, by using the absolute and the percentage calculations. This is done by computing each separately and selecting the lesser of the two. In this example, the computation would yield the following options: (0.102 x 0.95 = 0.0969) OR (0.102-0.005 = 0.0970). Because the lesser of these is 0.0969, that will be the correct lower tolerance limit; and (e) finally, by comparing all four of the reported test sample results (0.100, 0.101, 0.104, 0.103) against this accepted tolerance range of 0.0969 to 0.1071, it becomes plain that, in this example, the AIR is valid because all four test results fall within the accepted tolerance range. Because the Firmware version 3.11 utilized a doubled tolerance range, there will be AIRs that will not meet the test for tolerance that we have deemed to be permissible. We therefore provide a further example to illustrate the calculations relating to an AIR that would be out of tolerance under this standard and, therefore, inadmissible in a prosecution. If, for example, a defendant's first breath test sample yielded an IR result of 0.089 percent BAC and an EC result of 0.080 percent BAC, and the second sample yielded an IR result of 0.091 percent BAC and an EC result of 0.084 percent BAC, the calculations, which would be performed in the same manner, would yield a different outcome, as follows: (a) first, all four of the results (two IR and two EC) would be added, in this example, 0.089 + 0.080 + 0.091 + 0.084 = 0.344; (b) next, the arithmetic mean would be derived by dividing that sum by four, 0.344 / 4 = 0.086; (c) then the upper limit of acceptable tolerance must be determined by comparing the two methods for computing the range, namely, the use of the absolute or the percentage. This is done by computing each separately and selecting the greater of the two. In this example, the computation would yield the following options: (0.086 x 1.05 = 0.0903) OR (0.086 + 0.005 = 0.0910). Because the greater of these is 0.0910, that will be the correct upper tolerance limit; (d) next, the lower limit of acceptable tolerance must be derived by comparing the two methods for computing the range, again, by using the absolute and the percentage calculations. This is done by computing each separately and selecting the lesser of the two. In this example, the computation would yield the following options: (0.086 x 0.95 = 0.0817) OR (0.086-0.005 = 0.0810). Because the lesser of these is 0.0810, that will be the correct lower tolerance limit; and (e) finally, by comparing all four of the reported test sample results (0.089, 0.080, 0.091, 0.084) against this accepted tolerance range of 0.0810 to 0.0910, it becomes plain that, in this example, the AIR is invalid because the first breath sample's EC result (0.080) does not fall within the accepted tolerance range. The use in Firmware version 3.11 of the doubled tolerance range, which we have rejected, requires that all AIRs that report results of only two breath samples be tested for validity against the tolerance range we have accepted. Therefore, in all prosecutions stayed by our January 10, 2006 Order, the State shall review the BAC results as reported in the AIR and shall calculate whether those results fall within tolerance, and the court shall review those calculations and make them a part of the record. In those cases in which this review reveals that the results fall outside of the acceptable tolerance, the AIR cannot be deemed to be sufficiently scientifically reliable to be admissible and it shall not be admitted into evidence as proof of a per se violation.