The Alcotest 9510 in New Jersey DWI Cases
Reviewed by William A. Proetta, Esq. · Updated
The Alcotest 9510 is the breath-testing instrument police in most of New Jersey now use to measure blood alcohol content in DWI cases, replacing the older Alcotest 7110. A 9510 reading of 0.08% or higher is the State’s main evidence in most alcohol DWI cases, but the number is only as reliable as the procedures behind it. William Proetta Criminal Law reviews the instrument records, the operator’s certification and the testing procedure in every breath test case. Call (732) 659-9600 for a free case review.
From the 7110 to the 9510
| When | What happened |
|---|---|
| 2008 | In State v. Chun, the New Jersey Supreme Court found the Alcotest 7110 scientifically reliable, subject to conditions on how it is maintained and used. |
| By early 2023 | The State began replacing the 7110 with the 9510, starting with Monmouth County agencies and expanding to Middlesex County and the State Police. |
| May 1, 2023 | The Supreme Court took up State v. Cunningham, a challenge to the 9510’s scientific reliability, appointed Judge Richard J. Geiger to develop a record, and paused certain DWI cases relying on the 9510. |
| 2025 | The State Police still trained new 7110 operators only in Bergen, Essex and Camden counties, and scheduled existing 7110 operators for conversion to the 9510. |
| December 19, 2025 | After the defendant withdrew her challenge, the Court dismissed the appeal and lifted the stay. It made no finding that the 9510 is reliable and said individual defendants may still challenge it. |
What the 9510 Ruling Means for Your Case
Because the Court never ruled on the 9510’s reliability, there is no Chun-style decision approving the newer device. Prosecutions using 9510 readings went forward again after December 2025, but a defendant can still challenge the instrument’s reliability in an individual case. Whether that challenge makes sense depends on the evidence, the cost of expert testimony and what else the State can prove without the reading.
How a Breath Test Result Is Challenged
- The operator. The officer who ran the test must hold a current operator certification for the instrument used.
- The observation period. Officers must watch the driver before the test to make sure nothing in the mouth, such as burping or regurgitation, affects the sample.
- The instrument’s records. Calibration, maintenance and repair records, and the data the instrument stores, can show problems with a particular device.
- The samples. Incomplete or inconsistent breath samples can undermine the reported result.
See Challenging Breath Test Evidence in a New Jersey DWI Case for the full defense approach.
The Alcotest 7110 and Older DWI Cases
The Alcotest 7110 MKIII-C was New Jersey’s breath test instrument for well over a decade, and State v. Chun set the rules for using it. If your case involves a 7110 reading, from an older arrest or from a county still using the 7110, those Chun requirements and the 7110’s own maintenance records are where the defense starts. The 7110 also matters in post-conviction and expungement questions about older DWI convictions.
Refusing the Test
Refusing to give breath samples is a separate offense with its own license and ignition interlock penalties. See breath test refusal and ignition interlock requirements.
Alcotest 9510 FAQs
Is the Alcotest 9510 accurate?
No New Jersey court has ruled that it is scientifically reliable. The Supreme Court’s 2023 review ended in December 2025 without a ruling, and defendants may still challenge it case by case.
Is the Alcotest 7110 still used in New Jersey?
It is being phased out. As of the State Police’s 2025 training schedule, new 7110 operators were trained only in Bergen, Essex and Camden counties.
Can I beat a breath test result?
Sometimes. Problems with the operator’s certification, the observation period, the instrument’s records or the samples can lead to the reading being excluded or given less weight.
What BAC is a DWI in New Jersey?
0.08% or higher for drivers 21 and over and 0.04% for commercial drivers. For drivers under 21, any reading of 0.01% or more can lead to a separate underage offense.
Can I refuse the Alcotest?
You can, but refusal is its own offense with license and ignition interlock penalties.
Talk to a New Jersey DWI Lawyer
The sooner we review the evidence, the more options you have. Call William Proetta Criminal Law at (732) 659-9600 for a free, confidential case review. Available 24/7, and se habla español.