A DUI charge is built from details. Each one is defensible.

New Jersey DUI/DWI Law Overview

In New Jersey, driving under the influence of alcohol or drugs is prosecuted under N.J.S.A. 39:4-501. Unlike most other states, New Jersey treats DWI as a traffic offense rather than a criminal charge, meaning it is heard in municipal court and does not result in a criminal record upon conviction. However, the penalties are serious, including mandatory license suspension, installation of an ignition interlock device, substantial fines and surcharges, and possible jail time. A DWI conviction also remains on your driving record permanently in New Jersey because the state does not allow expungement of traffic offenses.

At Simon Law Group, our DUI/DWI defense attorneys represent drivers charged with impaired driving throughout New Jersey. Whether you were stopped at a sobriety checkpoint, involved in an accident, or pulled over for a traffic violation that escalated into a DWI arrest, we examine every aspect of the state's case to build a fact-specific defense.

The Alcotest and Breathalyzer in New Jersey

New Jersey has long relied on the Draeger Alcotest 7110 MK III-C as its standard breath-testing instrument and is transitioning statewide to the newer Alcotest 9510; after the New Jersey Supreme Court lifted its limited stay in December 2025, prosecutions using the 9510 are proceeding, and the 9510 has not received the blanket reliability endorsement the 7110 received, leaving it open to case-by-case challenge. Breath results are a central piece of evidence in most DWI prosecutions, but those results are admissible only if the State can demonstrate that the device was properly calibrated, maintained, and operated according to the strict protocols the New Jersey Supreme Court laid down in State v. Chun, 194 N.J. 54 (2008)1. That ruling is what gives the defense leverage: it converted the Alcotest from an unquestioned number into a result the State must affirmatively prove it earned, foundational document by foundational document.

Our attorneys challenge Alcotest results by investigating:

• Whether the device was calibrated within the required timeframe and with certified reference solutions
• Whether the operator held a valid certification and followed the required observation period of at least twenty minutes before administering the test
• Whether foundational documents, including calibration records and inspection certificates, were produced in discovery
• Whether radio frequency interference, mouth alcohol, or medical conditions such as gastroesophageal reflux could have affected the reading
• Whether the instrument's internal diagnostics reported any error codes or anomalies during testing

Where one of these challenges succeeds, the court can suppress the breath-test reading. What that suppression is worth depends on what evidence remains: with the central number gone, some cases move toward dismissal, others toward a reduction, and others simply toward a stronger negotiating posture. We do not promise an outcome; we identify which of these challenges the record actually supports before advising on a plea.

Field Sobriety Tests

Before or in addition to a breath test, officers typically administer standardized field sobriety tests (SFSTs) during a DWI stop. The three tests recognized by the National Highway Traffic Safety Administration are the Horizontal Gaze Nystagmus test, the Walk-and-Turn test, and the One-Leg Stand test. Officers rely on these exercises to build probable cause for an arrest, but they are not the objective measuring instruments they are sometimes treated as. They depend on the officer's stance, instructions, and scoring, and on the conditions on the roadside that night.

Field sobriety tests can be compromised by numerous factors unrelated to intoxication, including uneven road surfaces, poor lighting, footwear, physical disabilities, inner ear conditions, anxiety, fatigue, and the officer's own failure to administer the tests according to NHTSA protocols. Our attorneys review dashcam and bodycam footage to identify improper administration and challenge the reliability of SFST results.

Refusal to Submit to Breath Testing

Under New Jersey's implied consent law, N.J.S.A. 39:4-50.21, every person who operates a motor vehicle on New Jersey roads is deemed to have consented to breath testing when an officer has reasonable grounds to believe the driver is intoxicated. Refusing to provide a breath sample is a separate offense prosecuted under N.J.S.A. 39:4-50.4a2, and it carries penalties that are virtually identical to those imposed for a DWI conviction at the same offense level.

A refusal conviction requires the State to prove three elements: the officer had reasonable grounds to believe the driver operated a vehicle while intoxicated, the officer requested a breath sample, and the driver refused to provide the sample. Defenses include challenging the officer's reasonable grounds, demonstrating that the driver was not clearly informed of the consequences of refusal, or establishing that a physical or medical condition prevented compliance.

Penalties by Offense

New Jersey grades DUI/DWI penalties by how many prior convictions a driver has and, on a first offense, by the breath-test reading. The figures below reflect the statutory ranges under N.J.S.A. 39:4-501. The exact penalty in any given case depends on the BAC the State can prove, the timing of any prior offense, and whether a refusal or related charge is also in play, so treat these as the framework the court works within rather than a fixed sentence.

First Offense DWI

A first DWI offense in New Jersey carries penalties that vary based on blood alcohol concentration. For a BAC of 0.08% to less than 0.10%, the driver faces a license suspension until an ignition interlock device is installed, a fine of $250 to $400, up to 30 days in jail, 12 to 48 hours at the Intoxicated Driver Resource Center, a $1,000 annual insurance surcharge for three years, and additional court costs and penalties. For a BAC of 0.10% to less than 0.15%, fines rise to $300 to $500 and the interlock period runs 7 to 12 months. At 0.15% or higher, a four- to six-month license forfeiture applies, with the interlock required during the forfeiture and for 9 to 15 months after restoration.

Second Offense DWI

A second DWI offense within ten years results in a mandatory one- to two-year license suspension, a fine of $500 to $1,000, a minimum of 48 consecutive hours in county jail (up to 90 days), 30 days of community service, mandatory installation of an ignition interlock device for two to four years after license restoration, and the $1,000 annual insurance surcharge for three years. The court may also impose additional conditions such as alcohol education or treatment programs.

Third and Subsequent Offenses

A third or subsequent DWI offense carries the most severe consequences: an eight-year license suspension, a fine of $1,000, a mandatory 180-day jail sentence (although up to 90 days may be served in an inpatient rehabilitation facility), mandatory ignition interlock for two to four years after restoration, and the three-year insurance surcharge. The cumulative financial impact can be substantial once fines, surcharges, interlock costs, insurance effects, employment disruption, and lost income are considered.

The Intoxicated Driver Resource Center

New Jersey requires first and second DWI offenders to spend time at an Intoxicated Driver Resource Center (IDRC). First offenders must complete 12 to 48 hours of detention and education at the IDRC, while second offenders must complete 48 hours. The IDRC program includes screening, evaluation, and referral for alcohol and drug treatment. Failure to comply with IDRC requirements results in additional license suspension until the program is completed.

Ignition Interlock Device Requirements

Since December 2019, New Jersey law requires installation of an ignition interlock device for most DWI convictions, including first offenses. The interlock device requires the driver to provide a breath sample before the vehicle will start and periodically while driving. The duration of the interlock requirement depends on the offense level and BAC reading under N.J.S.A. 39:4-50.171. Tampering with or circumventing the device is itself a separate motor-vehicle offense that carries additional penalties.

Related Charges and Consequences

A DWI arrest frequently involves additional charges that can compound the consequences. These include disorderly persons offenses such as reckless driving, driving while suspended, open container violations, and eluding police. When a DWI results in injury or death, the driver may face indictable criminal charges including assault by auto or vehicular homicide, which carry prison sentences measured in years rather than days.

For an overview of how impaired driving enforcement ramps up during warmer months, including checkpoint strategies and enhanced patrol operations, see our article on summer DUI rates and enforcement trends.

Our DWI Defense Approach

No two DWI cases carry the same exposure, and no defense is a foregone conclusion, but every case has a record that can be tested, and that testing is where defenses are found. Our attorneys begin with a thorough review of the traffic stop itself, examining whether the officer had reasonable suspicion to initiate the stop and probable cause to arrest. We obtain and analyze all discovery materials, including police reports, Alcotest foundational documents, calibration records, video evidence, and dispatch records. When warranted, we retain expert witnesses in toxicology and breath-testing science to challenge the State's evidence.

Depending on the facts, our defense strategies may include:

• Filing motions to suppress evidence obtained through an illegal stop or arrest
• Challenging the Alcotest results based on calibration deficiencies, operator error, or medical conditions
• Disputing the officer's observations and interpretation of field sobriety test performance
• Negotiating a reduction to a lesser traffic offense such as reckless driving where the evidence supports it
• Presenting evidence of rising blood alcohol to argue that the defendant's BAC was below the legal limit at the time of driving

Which of these strategies fits a given case is a question of the record, not of optimism. We review the discovery, identify the challenges the facts actually support, and tell you honestly where the strengths and the exposure lie, including when the right move is to negotiate rather than to fight. The goal is the best result the facts will bear, reached with a clear-eyed read of the State's case rather than a promise about its outcome.

Review the stop and testing before choosing a path

License-restoration requirements, ignition-interlock issues, and the 20-day appeal window from a municipal-court conviction under R. 3:23-2 can create separate deadlines. Use the consultation formto identify the stop, testing, refusal allegation, prior record, county, and next court date.

Related criminal-defense practice areas

• Criminal Defense pillar: the broader criminal-defense framework and the procedural infrastructure for indictable and disorderly-persons matters
• Disorderly Persons Offenses: municipal-court framework for non-indictable matters that frequently accompany DUI charges
• Pretrial Intervention & Diversion: PTI, Conditional Discharge, Conditional Dismissal, and the State v. Wallace prosecutor-objection-override framework
• Expungement & Clean Slate: clearing eligible records under N.J.S.A. 2C:52; note that DUI/DWI convictions are not eligible for expungement under NJ law
• Post-Conviction Relief: petitions to vacate convictions on ineffective-assistance, newly-discovered-evidence, or constitutional grounds under R. 3:22
• New Jersey criminal statutes guide: a reference to Title 39 driving offenses and the Title 2C sections that most often accompany a DWI arrest