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Reviewing New Jersey v. Chun in Light of Massachusetts Source Code Challenge

In 2008, the New Jersey Supreme Court decided, New Jersey v. Chun, which was the first case where the Court addressed whether the source code of the Alcotest 7110 was scientifically reliable. This is the leading case on the issue of the source code. Massachusetts OUI Lawyers are currently conducting a similar hearing for the newer Alcotest machine the 9510. In this Blog, we will review the findings of the Chun case as the decision will have an impact on how the judge rules in the Consolidated appeal being heard in the Concord District Court.  Currently, the Source code reliability hearing is scheduled for March 14 and is scheduled to take until March 17th.

One of the major differences between Chun and the current hearing in Massachusetts, is that the hearing in Concord involves a different machine, the Alcotest 9510, which has a much more complex source code than the Alcotest 7110.  There is currently a hearing in the Ayer District Court on the 7110 machine; this hearing will effect fewer cases as many case involving the 7110 have been resolved; however, it could result in new trial motions being filed should the court find the source code unreliable.

The first issue addressed by the Chun Court was whether the Blood/Breath partition ratio was scientifically reliable. The breath test converts a breath test result into a blood alcohol percentage by using a conversion factor. The Court found that the use of the partition ratio was accepted in the scientific community and would only overstate the blood alcohol content for a small percentage of defendants. While the Court did not state the percentage, it is believed to be as high as 30%. 

In Chun, the defendant’s claimed that the minimum breath liter volume should be reduced to 1.2 liters for all persons; the Court approved a change to reduce the minimum breath volume to 1.2 liters for those over 65.  The Court found that most States use 1.5 liters, though Alabama use 1.3 liters.

The Court explained that the 1.5 liters was what is believed to be how much air is needed to produce deep lung air where the alcohol concentration at the end of the breath reaches an end point. As a person blows into the machine, the blood alcohol concentration increases. At 1.5 liters it is believed that the machine will sample deep lung air which should according to the Government’s theory reflect the blood alcohol concentration.

The Chun Court declined to lower the minimum breath volume and made this change applicable only to those over 65.

The Special Master required that New Jersey purchase the optional tempeture sensor as the breath test assumes that the expired breath is 34 degrees Celsius. If the temperature were 35 degrees the breath alcohol percentage would be 6.5 higher. The special master recommended reducing the results for all tests by 6.5 percentage and the purchase of the optional sensor. The New Jersey Supreme Court overturned this finding by the Special Master.

On March 17th, 2008, the Court decided that the findings of the Special Master who had determined that the Breathalyzer test is an accurate measure of a person’s blood alcohol levels, to be adopted. However, after extensive research, although the Court found that there is no reason to believe that the Breathalyzer that is so commonly used is not a valid device, they did find that there were some errors with the mechanics of the device.

The Court recommends that the device be recalibrated with use. As the device ages, its accuracy will decrease. To get more accurate readings, the Breathalyzer will need to be calibrated annually. Secondly, the Court and the Special Master recognized the buffer overflow defect. This error must be corrected in all forms of software, because the defect causes some breath test results to produce an incorrect reading. Additionally, the Special Master did order that if a third breath sample is taken, then the AIR should be recalculated to a correct formula, and that AIR should be inadmissible in any case that has data missing from it. The Court also requested that officers look at each breath test reading separately and take the lowest acceptable range out of all of the recorded results. Accordingly, the Special Master requested that any changes to the breath test devices and firmware should be published and known to the NJSBA. Interestingly, the Special Master requested that the defendants’ source code corrections be considered whenever any changes are being implemented into the firmware.

The Special Master had also requested that the catastrophic error detection feature of the Alcotest be re-enabled. This means that in the event of a catastrophic error, the device will stop and restart. This will further ensure that results of the Breathalyzer will be accurate and reliable.

Although the Court believes that in general, the Breathalyzer is a reliable form of evidence and takes accurate measurements, they did request that the Special Master’s orders be put into place in order to better the overall device. Secondly, the Court decided that defense attorneys and their experts should be given the option to receive training on how the breath test works exactly.  Recently, the Massachusetts Courts ordered defense attorney to have access to the training of officers regarding the breath test; while a few attorneys have attended this training, it is questionable whether this was the same training officers received when defense lawyers are not present.

EC and IR Fuel Cell Drift

In Chun, Brian Shaffer a Drager employee responsible for the source code testified that the EC reading is obtained by passing electric current through a small sample of breath that has been other capture for IR testing. The reaction of the fuel cell can be represented graphically as a curve and the percentage of alcohol in the breath is measured by calculating the area under the curve mathematically.

He explained that as fuel cells age, the area under the curve that expresses the same breath alcohol content is unchanged, but the shape of the curve itself changes from a higher sharp peak to a flatter one. Dragger claims that the fuel cell drift results in an under reporting of alcohol percentage. To compensate for this Drager adjusted the algorithm in the software. The software increase the EC reading to account for the under reporting caused by the fuel cell drift.

The New Jersey Supreme Court rejected the defendant’s argument that the fuel cell drift undermined the accuracy and reliability of the breath test machine.

The Chun case is likely to be cited by the Court in the Massachusetts Source Code challenge.  I expect the testimony will show that there has been changed in the software and the machine since 2008; additionally, since the experts will be different in the two cases the Court will hear different evidence explaining the problems with the breath test machine.  Further, in the current challenge defense lawyers also have a separate challenge to the calibration of the machine which was not an issue for the Chun Court.  To read more about the Chun case, there is a wealth of information on the website of lead counsel in that case Evan Levow.  

To learn more about the breath test accuracy and defending an OUI case, you can visit Attorney DelSignore website and page as well as call 781-686-5924 to ask your questions.




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