New Jersey law allows prosecutors to establish that a defendant charged with driving while intoxicated (DWI) was legally impaired by showing that the amount of alcohol in their blood around the time of their arrest was above a minimum amount. Most police departments in New Jersey use a device known as an Alcotest to determine BAC by testing a sample of a suspect’s breath. In order to ensure that a device gives accurate readings, it must have regular maintenance and calibration. A 2008 New Jersey Supreme Court decision, State v. Chun, established standards and procedures that police must follow regarding both the maintenance of the device and the manner in which breath samples are obtained. In 2016, a State Police Sergeant was accused of submitting false Alcotest maintenance reports. This led to an order staying all pending New Jersey DWI cases that might involve evidence obtained from devices serviced by this officer. A recent report from a court-appointed special master stated that the improper calibration “undermine[s] or call[s] into question the scientific reliability of breath tests performed” with those devices.
An individual is presumed to be legally impaired, for the purpose of the New Jersey DWI statute, if their BAC is 0.08 percent or more. Prosecutors have used a variety of devices over the years, often collectively known as “breathalyzers,” to measure BAC from breath samples. New Jersey police began using the Alcotest device in the late 1990’s and early 2000’s. By the mid-2000’s, most police departments around the state were using this device. Since a defendant’s BAC measurement is one of the state’s most important pieces of evidence, confirming that the Alcotest reliably gives accurate readings is critically important. We were involved in the Chun case, which resulted in a series of standards for maintaining and calibrating Alcotest devices, and procedures for reporting on the devices’ regular maintenance.
The chemical processes that the Alcotest device uses to measure BAC require careful calibration. The device uses “simulator solutions” as controls, which must be kept within a specified temperature range. The individual performing the calibration must use a certain type of thermometer to measure the temperatures of the solutions. If any of the solutions are not within the required temperature range, the device may not give accurate readings. Chun states that maintenance reports, showing that calibrations were performed within these guidelines, must be made available to defendants or their counsel.