New Jersey DWI Attorney Blog
What to Know About the Current State of Alcotest Device Usage in New Jersey DWI Cases
The offense of driving while intoxicated (DWI) in New Jersey requires proof that a driver was impaired by alcohol or drugs. Whenever possible, prosecutors use the results of breath testing that shows a defendant’s blood alcohol concentration (BAC). New Jersey police measure BAC with a device known as the Alcotest. This is a complex device that requires routine maintenance to ensure it provides accurate results. Our law firm has been involved in litigation to ensure prosecutors must prove that Alcotest devices have received the required maintenance. A recent order from the New Jersey Supreme Court affects DWI cases with evidence obtained from a newer Alcotest model. The order highlights the importance of having a knowledgeable DWI attorney on your side.
Courts often perceive BAC evidence as reliable because it is a direct measurement of alcohol in a person’s breath. Without BAC evidence, the state must rely on officer testimony. For example, an officer might testify that they saw a car driving erratically, and that the driver slurred their speech when the officer questioned them. The law presumes a person with BAC of at least 0.08 percent is too impaired to drive safely or legally. This all depends on accurate measurements, though.
New Jersey police used the Alcotest 7110 for many years. A person must blow into a tube to provide a breath sample. The device uses chemical reactions to measure the amount of alcohol in the sample. From this, it estimates the amount of alcohol in the person’s bloodstream. If the device does not have the necessary chemicals in the right amounts and proportions, it will not provide accurate results.
We were involved in a case that led to a 2008 ruling from the New Jersey Supreme Court, State v. Chun. This decision established procedures for calibrating Alcotest devices. Police departments must keep records showing when each device last received maintenance. These reports are part of any DWI case that relies on Alcotest BAC results.
The Chun decision specifically deals with the Alcotest 7110. In recent years, most New Jersey counties have switched to the newer Alcotest 9510. According to information from the state police, as of 2025 only Bergen, Essex, and Camden Counties still use the Alcotest 7110. The procedures established in Chun still apply to the Alcotest 9510, but it is a new device that may present new problems.
In 2023, a DWI defendant challenged the reliability of Alcotest 9510 results. The New Jersey Supreme Court issued a stay on certain pending cases that involved these devices. After two years of litigation, the defendant asked to withdraw her challenge to the Alcotest 9510’s scientific accuracy. The court lifted the stay in December 2025.
The court’s order does not find that the Alcotest 9510 is accurate. The device is still open to legal challenges. The requirements of Chun remain in effect. DWI defendants have a right to information about the device used in their case. They can challenge the BAC results if the maintenance was inadequate or the records are flawed.
New Jersey police and courts take DWI very seriously. The legal process and court system can be complicated and confusing. An experienced and skilled DWI lawyer can help you understand your rights and advocate for you with prosecutors and the judge. Evan Levow has dedicated 100% of his law practice to defending people facing New Jersey DWI charges. Please contact us today, online or at (877) 593-1717, to schedule a free and confidential consultation with a member of our team to see how we can help you.