Can You Trust Preliminary Alcohol Screening Devices?

February 28th, 2020 | Posted by CCAPP in Addiction | Health & Wellness | Impaired Driving | Policy

TSRP & LFS Responds to New York Times Article

On November 3, 2019, the New York Times published an article about Preliminary Alcohol Screening (PAS) devices. The article was titled, These Machines Can Put You in Jail. Don’t Trust Them.” The Traffic Safety Resource Prosecutors (TSRP) released a statement (below) as it relates to the article. On February 6, 2020, the Sacramento County Laboratory of Forensic Services also responded to the article.

TSRP Response

“Persons who repeatedly drive drunk present a greatly enhanced danger that they and others will be injured as a result. In addition, it has been estimated that the ratio of DUI incidents to DUI arrests is between 250 to 1 and 2,000 to 1.” Begay v. U.S., 128 S Ct 1581 (2008) Alito dissent at 1593-4.

The Times published an article on November 3 headlined “These Machines Can Put You in Jail. Don’t Trust Them.” This article disparages all breath testing instruments and demonstrates a failed understanding of impaired driving detection, investigation, and prosecution. The failures include: an inaccurate portrayal of the instruments used to help law enforcement officials do their jobs; an incomplete picture of the various tests performed by trained law enforcement officials following a traffic stop; and overreliance on paid defense “experts” whose testimony has been overruled in court rooms throughout the United States.

The article demonstrates a misunderstanding of how breath testing instruments work. Modern instruments rely on infrared and electro-chemical fuel cell technology, which is proven to be accurate and reliable. The instrument tests itself, and when used properly, will not allow a test that is unfair to the driver. Some States, including North Carolina, require two consecutive tests to ensure accuracy.

Particularly discouraging is the lack of attention to accuracy in the article. For example, the claim that manufacturers are hiding-the-ball on their software is a common and repeatedly disproven conspiracy theory spun by DWI defense attorneys. The article specifically claims Draeger, the manufacturer of the Alcotest 9510, was forced by courts to reveal its source code. That is simply not true. The facts are in published cases and filed court documents. Draeger voluntarily provided its source code in New Jersey, Massachusetts, and Washington State, under a protection order reviewed and approved by the State courts. Other manufacturers have similarly provided their source code with an appropriate protection order. In all the states where the defense examined the software, the court ultimately agreed the tests were admissible. In other words, after more than a decade of examining breath test software and a mountain of public funds, no court has excluded a breath test based on any software issue. Software challenges are simply a way for DWI defense attorneys to delay cases for years while thousands of DWI cases languish and eventually fade away, too stale to prosecute. Misstating the facts is an unfair way to reinforce a narrative.

Furthermore, it should be noted these tests — whose accuracy is the crux of the article — are performed after the driver has been arrested based on probable cause. An officer who offers an evidential breath test to a driver has already established evidence of impairment sufficient to support the arrest at roadside. The breath test simply confirms and corroborates the trained officer’s observations that were gathered through a litany of roadside tests prior to the arrest and breath testing being offered. This reality represents another inaccuracy depicted in the article.

The authors repeatedly reference field sobriety tests, including a “counting test”. At no point in their article do the authors reference the Standardized Field Sobriety Tests, which have been studied, evaluated, and approved over decades. These tests are invaluable in the investigative process and help ensure an officer is fully doing his or her job. Officers in all 50 States and the District of Columbia, as well as Canada, Germany, Australia, and the United Kingdom use this three-test battery in impaired driving investigation.

Any officer investigating an impaired driving offense must be able to cross several hurdles. First, they must show reasonable, articulable reasons for the stop, should the vehicle be in motion. These reasons include traffic violations, equipment violations, or other indicators of impaired driving. Other cases, such as crashes and checking stations, do not involve this phase of detection. Once contact with the driver is made, the officer must develop probable cause for the arrest.

LFS Response

The Sacramento County District Attorney’s Laboratory of Forensic Services (LFS) is Nationally Accredited by ANAB – The American National Standards Institute and only hire Criminalists that have, at minimum, a Bachelor of Scientific Degree in Forensic Science or a Natural Science.  The LFS Criminalists receive training from staff with extensive scientific training, various professional organizations, specialized university programs, federal and state institutions, as well as, instrumentation manufacturers.  The LFS Criminalists receive ongoing training each year in their areas of expertise.

The current instrumentation employed by the LFS for evidential breath testing is the Dräger Alcotest 9510. This instrument measures breath alcohol levels by two different technologies, fuel cell & infrared detection, to ensure accurate results.  Calibration of our instruments is always performed by the manufacture. 

When the LFS receives calibrated instruments from Dräger they are verified for accuracy over their linear range (0% to 0.40%) using 6 National Institute of Technology (NIST) traceable standards before deployment. These calibration standards are purchased from Intoximeters which has an ISO 17025:2005 Calibration Laboratory Accreditation from the American Association for Laboratory Accreditation (A2LA).

After the instrument accuracy is verified, a pre-installation maintenance test is performed to ensure the instrument detects and reports all testing errors. It is the LFS policy that all repairs are performed only by the manufacture. All instruments are sealed with screws that require a specialized key; therefore, the LFS has never accessed the internal components of any instrument. 

All local and state law enforcement agencies in Sacramento County are trained by authorized LFS staff members on the LFS testing method prior to use.  A breath testing method\checklist is required to be completed and signed by the operator with each test, which was designed to eliminate potential operator errors.

The LFS releases a Periodic Accuracy Check record that includes the date of each test, results of both technologies, the NIST traceable standard concentration and lot number used to evaluate the accuracy.  In addition, we provide a monthly Maintenance Record and Subject Test Log for each instrument, which includes repairs and any of errors that occur with each subject test.    The preliminary alcohol screening (PAS) devices mentioned in the article are not supported by the LFS.  Each local law enforcement agency in Sacramento are responsible for their programs’; therefore, I cannot speak to their method(s) of testing or the accuracy of their results.

Below is a link to view the LFS response in PDF on their letterhead.

We wish to thank the Strategic Highway Safety Plan, Impaired Driving Challenge Area for providing this information and giving permission to post.

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