When prosecutors in New Jersey pursue a case of alleged driving while intoxicated (DWI), they frequently rely on evidence of a defendant’s blood alcohol content (BAC) obtained through breath or blood testing. Anyone with a BAC of 0.08 percent or above is presumed to be impaired for the purpose of a DWI case. Police in this state typically use a device known as an Alcotest to collect and test breath samples from DWI suspects. We were counsel in a case that went before the New Jersey Supreme Court in 2008, State v. Chun, which established multiple guidelines that the state must follow in order to use BAC evidence obtained with an Alcotest device. The state Supreme Court recently reversed a DWI conviction in another case, State v. Kuropchak, based on improper documentation regarding the Alcotest used by police.
Police in New Jersey currently use the Draeger Alcotest® 7110 MKIII-C. The DWI suspect blows into a tube, and the device analyzes the breath sample to estimate the person’s BAC. It bases its estimate on a “2,100 to 1 blood/breath alcohol ratio,” meaning that its programming assumes that 2,100 parts of breath contain the same amount of alcohol as one part of blood. This assumption was one of the many features of the Alcotest that were challenged in Chun.
The New Jersey Supreme Court ruled in Chun that the Alcotest is generally acceptable by scientific standards, but it imposed a variety of conditions on police using the device, and on prosecutors seeking to admit BAC evidence obtained with the device. The state must produce two documents relating to the calibration and maintenance of the device. It must produce a Certificate of Analysis showing that the device has the proper “simulator solution,” a solution typically designed to return a 0.10 percent result to use as a comparison to the breath sample. The state must also produce the most recent report documenting maintenance of the device, known as the “Calibrating Unit New Standard Solution Report.”
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