How the Alcotest Is Challenged in New Jersey DWI Cases

In most New Jersey drunk driving cases, the most important piece of evidence is a number printed by a machine. The Alcotest is the breath testing device used by police throughout the state, and its reading often determines whether a driver faces a per se DWI charge. Because so much depends on that single result, the reliability of the test is frequently the focus of a defense. Drivers who speak with a DUI Attorney Fort Lee NJ residents often learn that a breath test reading is not the end of the story, but the beginning of a detailed review.

Understanding how the Alcotest works, and where it can go wrong, helps explain why these results are not automatically accepted in court.

What the Alcotest Measures

The Alcotest estimates blood alcohol concentration by analyzing a sample of deep lung air. The device uses two separate technologies, infrared and electrochemical analysis, to measure alcohol in the breath. The two readings must agree within a set tolerance, and the driver must provide at least two acceptable samples.

Under New Jersey law, a reading of 0.08 percent or higher can support a DWI conviction on its own, without any other proof of impairment. A reading of 0.10 percent or higher triggers enhanced penalties. Because the stakes rise with each hundredth of a point, even a small error can change the outcome of a case.

The Foundation Set by the New Jersey Supreme Court

The admissibility of Alcotest results traces back to the New Jersey Supreme Court's decision in State v. Chun. In that case, the Court found the device scientifically reliable, but only when it is properly maintained, properly operated, and supported by specific documentation. The Court also ordered certain changes to the device and its software.

This framework matters because it gives the prosecution a clear burden. Before a breath reading can be used as evidence, the State must show that the required procedures were followed. When any part of that foundation is missing or flawed, the result may be challenged or excluded.

Common Grounds for Challenging the Alcotest

The 20 Minute Observation Period

Before administering the test, an officer must observe the driver continuously for at least 20 minutes. During that time, the driver should not eat, drink, smoke, or have anything in their mouth. If the driver belches, hiccups, or regurgitates, the observation period is supposed to start over.

The purpose is to make sure residual mouth alcohol does not inflate the reading. If the officer was completing paperwork, looking away, or dealing with other tasks during this period, the validity of the observation may be questioned. Booking room video is often reviewed to confirm whether the observation actually took place.

Operator Certification

Only officers who hold a current certification may administer the Alcotest. If the operator's certification had expired or cannot be documented, the reading may be inadmissible. Certification records are a routine part of discovery in New Jersey DWI cases.

Calibration and Maintenance Records

Each Alcotest device must be periodically calibrated and checked by a trained coordinator. The State is expected to produce foundational documents showing that the specific device used was functioning properly. These typically include calibration records, certificates for the simulator solutions used in testing, and records of the device's control tests.

Gaps in these records, expired solutions, or irregular maintenance can all undermine confidence in a reading. A careful review of these materials is a central task in any DUI Defense Practice, particularly because a conviction can affect a driver's record for many years.

Lessons From the Calibration Scandal

New Jersey has firsthand experience with how calibration errors can affect thousands of cases. In State v. Cassidy, the New Jersey Supreme Court ruled that breath results from devices calibrated by a particular State Police coordinator were inadmissible because a required temperature check had been skipped. That decision affected more than 20,000 breath test results across several counties.

The case showed that calibration is not a technicality. When a required step is skipped, the scientific basis for the reading is compromised, and courts will not simply assume the result is accurate.

Medical and Physical Factors

Certain health conditions may affect breath test results. Acid reflux and gastroesophageal reflux disease can bring alcohol from the stomach into the mouth, potentially raising the reading. Dental work, such as bridges or dentures, may also trap residual alcohol.

Some individuals, including older drivers or those with respiratory conditions, may have difficulty producing the required breath volume. This issue is especially important because an inability to complete the test may lead to a refusal charge. Documented medical conditions can sometimes explain why a driver could not provide an adequate sample.

The Role of Discovery

Most Alcotest challenges begin with discovery. Drivers are entitled to request the materials the State intends to rely on, including the Alcohol Influence Report, calibration documents, operator credentials, and video recordings. These records allow every step of the testing process to be examined.

Sometimes the problem is not with the test itself, but with what happened before it. If the initial traffic stop lacked a lawful basis, or if probable cause for the arrest was missing, evidence that followed, including the breath test, may be suppressed.

Why These Challenges Matter

A New Jersey DWI conviction can bring license suspension, ignition interlock requirements, fines, surcharges, and mandatory attendance at the Intoxicated Driver Resource Center. Repeat offenses carry steeper penalties. Given these consequences, accepting a breath reading without examining how it was obtained can be a costly mistake.

Impaired driving is also only one of several driving behaviors that carry serious legal risk. Discussions of distracted driving and DUI consequences, including those referenced by Kratka Law Group, highlight how differently the law can treat behaviors that may seem similar on the road.

The Alcotest is a sophisticated instrument, but it is only as reliable as the people and procedures behind it. Observation periods, operator training, calibration, and medical factors all affect whether a reading truly reflects a driver's condition. In New Jersey, the law requires that each of those elements be satisfied before a number on a printout can decide a case.