Challenging the Traffic Stop in a New Jersey DWI Case

A New Jersey DWI case often begins with a traffic stop. Before an officer can pull over a vehicle, there generally must be a legally sufficient reason for the stop. If the officer lacked reasonable and articulable suspicion that a motor vehicle violation, criminal offense, or other lawful basis existed, the defense may be able to challenge the stop and seek suppression of the evidence obtained afterward.

That can be especially important in a DWI case because much of the State’s evidence is developed only after the vehicle has been stopped. The officer’s observations, statements made by the driver, field sobriety tests, arrest, and breath-test evidence may all flow from that initial encounter.

A successful challenge to the stop can therefore affect much more than the traffic violation itself. In some cases, evidence obtained after an unlawful stop may be excluded through a motion to suppress evidence.

What Do Police Need to Stop a Vehicle in New Jersey?

A motor vehicle stop is considered a seizure under both the United States Constitution and the New Jersey Constitution.

Police ordinarily need a reasonable and articulable suspicion that the driver or an occupant has committed a motor vehicle violation, criminal offense, disorderly persons offense, or that another legally recognized basis for the stop exists.

The State does not necessarily have to prove that the driver was ultimately guilty of the traffic violation used to justify the stop. The issue at a suppression hearing is generally whether the officer had an objectively reasonable factual basis for believing a violation had occurred when the stop was made.

Common Reasons Police Give for DWI Traffic Stops

DWI investigations frequently begin with an alleged motor vehicle violation rather than direct evidence that the driver is intoxicated.

Common reasons officers give for stopping a vehicle include:

  • Speeding — N.J.S.A. 39:4-98
  • Failure to maintain a lane — N.J.S.A. 39:4-88
  • Weaving or drifting — generally analyzed under N.J.S.A. 39:4-88 and sometimes N.J.S.A. 39:4-97 (Careless Driving) depending on the facts. Weaving within a lane is not itself a separate Title 39 offense.
  • Running a red light — N.J.S.A. 39:4-81 / N.J.S.A. 39:4-105, depending on the specific signal violation
  • Failure to stop at a stop sign — N.J.S.A. 39:4-144
  • Failure to signal — N.J.S.A. 39:4-126
  • Improper lane changes — N.J.S.A. 39:4-88 and/or N.J.S.A. 39:4-126
  • Driving unusually slowly / impeding traffic — N.J.S.A. 39:4-56 and/or N.J.S.A. 39:4-67
  • Following another vehicle too closely — N.J.S.A. 39:4-89
  • Equipment violations — varies by the alleged defect; generally Title 39, Chapter 3
  • Expired or unregistered vehicle — N.J.S.A. 39:3-4
  • Obstructed windshield or windows — N.J.S.A. 39:3-74
  • Window-tint violations — generally N.J.S.A. 39:3-74, subject to statutory exceptions and the case law interpreting what constitutes non-transparent tint.

The fact that an officer lists a motor vehicle violation in the police report does not automatically make the stop lawful. The defense can examine whether the facts actually supported the violation being alleged and whether the officer correctly understood the law.

Can Weaving Within a Lane Justify a DWI Stop?

Weaving within a single lane does not automatically constitute a violation of New Jersey’s failure-to-maintain-lane statute N.J.S.A. 39:4-88.

In State v. Maclay, an unpublished Appellate Division decision, the court recognized an important distinction: weaving within a lane is not the same thing as failing to maintain a lane. The court explained, however, that under appropriate circumstances unusual driving within a lane may still provide a reasonable indication that a driver is impaired or experiencing some other problem.

That means the word “weaving” by itself does not answer whether the traffic stop was lawful. The court must consider what actually happened and the totality of the circumstances.

Important questions can include:

  • How many times did the vehicle drift or move within the lane?
  • How long did the officer observe the vehicle?
  • Did the vehicle ever cross the center line, shoulder line, or lane markings?
  • Was the vehicle traveling significantly below the speed limit?
  • Were there curves, potholes, construction, weather, or other road conditions?
  • Did the alleged movement interfere with another vehicle?
  • What does the police dash-camera footage actually show?

The distinction matters because an officer may write “failure to maintain lane” in a report even though the video shows that the vehicle never left its lane. That discrepancy can become important when deciding whether the officer actually had a lawful basis for the stop.

This is one reason the defense should compare the officer’s written report against the objective recordings. See our guide to challenging police reports using body-worn camera footage in New Jersey.

At the same time, weaving within a lane can still contribute to reasonable suspicion when combined with other facts. New Jersey courts have upheld stops where unusual weaving occurred together with other indicators such as unusually slow driving or other abnormal vehicle operation.

So the defense should not simply ask, “Was the car weaving?” The more important question is: what exactly did the vehicle do, and was that conduct enough to legally justify the stop?

What If the Officer Was Wrong About the Law?

A DWI stop can also be challenged when the officer accurately observes what the vehicle is doing but incorrectly believes that the conduct violates New Jersey motor vehicle law.

One of the important New Jersey cases addressing this issue is State v. Puzio, 379 N.J. Super. 378 (App. Div. 2005).

In Puzio, a police officer stopped a passenger vehicle because it had commercial license plates but did not display the business owner’s name and address. The officer believed New Jersey law required that information to appear on the vehicle.

The problem was that the statute relied upon by the officer did not apply to the type of passenger vehicle involved.

The Appellate Division concluded that the stop was based on an erroneous interpretation of the statute and distinguished that situation from a case where an officer correctly understands the law but may be mistaken about the underlying facts.

That distinction can be important in DWI cases. An officer may accurately observe a driver’s conduct but still misunderstand whether that conduct is actually prohibited by the Motor Vehicle Code.

Later New Jersey cases have addressed when an objectively reasonable mistake of law may be treated differently, so the analysis is not as simple as saying that every legal mistake automatically invalidates a stop. The exact statute, the officer’s interpretation, and the circumstances all matter.

The defense should therefore examine both what the officer observed and whether New Jersey law actually prohibited it.

What About an Anonymous 911 Call?

A DWI stop does not always begin with an officer personally observing suspicious driving. Sometimes another motorist or witness calls 911 and reports a suspected
intoxicated driver.

The leading New Jersey Supreme Court case involving this issue is State v. Golotta, 178 N.J. 205 (2003).

In Golotta, police received a 911 report describing a vehicle that was being driven erratically and was reportedly “weaving back and forth.” The officer located the reported vehicle and stopped it without independently observing the same erratic driving.

The New Jersey Supreme Court upheld the stop and recognized that a contemporaneous 911 report of dangerous driving can carry greater reliability than an ordinary
anonymous tip. The Court emphasized the immediate public-safety concerns presented by a report of a dangerously operated vehicle.

But Golotta does not mean that every anonymous call automatically authorizes police to stop a car.

The defense should examine:

  • Whether the caller personally witnessed the driving
  • Whether the call was made while the conduct was happening
  • Exactly what the caller said the driver was doing
  • Whether the caller provided a license plate or detailed vehicle description
  • Whether police located the same vehicle described by the caller
  • How much time passed between the call and the stop
  • Whether the officer personally observed any suspicious driving
  • Whether the dispatcher accurately relayed the caller’s information to the officer

The actual contents of the call can be critical. A dispatcher telling an officer there is a “possible drunk driver” may not tell the full story of what the caller actually observed.

For that reason, the defense should seek the 911 recording, dispatch audio, CAD records, police reports, dash-camera footage, and body-camera
recordings whenever available.

What If the Police Followed the Vehicle Looking for a Reason to Stop It?

Police are generally permitted to follow a vehicle and observe how it is being operated. The important question is whether the officer ultimately developed a legally sufficient basis for initiating the stop.

In some DWI cases, the police report describes substantial weaving, erratic braking, delayed turns, or other unusual driving. The video may show something quite different.

The defense may compare:

  • The officer’s written report
  • Dash-camera footage
  • Body-worn camera footage
  • Dispatch recordings
  • CAD records
  • Motor vehicle summonses
  • The officer’s later testimony

Differences between the report and the recording can become important when challenging both the legality of the stop and the credibility of the officer’s observations.

For a broader discussion of this issue, see Challenging Police Reports Using BWC Footage in New Jersey.

Can an Equipment Violation Support a DWI Stop?

Yes, certain equipment violations can provide an independent basis for a traffic stop.

Examples may include:

  • Broken headlights or taillights — generally N.J.S.A. 39:3-66 and related lighting provisions in Title 39, Chapter 3
  • License-plate violations — N.J.S.A. 39:3-33 and related plate-display provisions
  • Windshield obstructions — N.J.S.A. 39:3-74
  • Improper window tint — generally N.J.S.A. 39:3-74
  • Registration problems — generally N.J.S.A. 39:3-4
  • Other equipment defects covered by the Motor Vehicle Code — various provisions of Title 39, Chapter 3, depending on the particular defect

But the alleged defect must actually provide a lawful basis for the stop. The defense should examine the exact statute relied upon by the officer and whether the vehicle’s condition actually violated that statute.

This is where cases involving mistaken interpretations of motor vehicle law, including State v. Puzio, can become especially relevant.

What Happens If the Traffic Stop Was Unlawful?

If the officer did not have a constitutionally sufficient reason to stop the vehicle, the defense can ask the court to exclude evidence obtained as a result of that stop.

This is generally done through a motion to suppress evidence.

A suppression motion asks the court to determine whether the police violated the Fourth Amendment to the United States Constitution or Article I, Paragraph 7 of the New Jersey Constitution.

In a DWI case, evidence developed after the stop can include:

  • The odor of alcohol
  • Bloodshot or watery eyes
  • Slurred speech
  • Statements about drinking
  • Admissions concerning driving
  • Field sobriety test observations
  • Roadside video evidence
  • Breath-test results
  • Drug-impairment observations
  • Blood or urine evidence

If those items were obtained only because of an unconstitutional stop, the defense may argue that they should not be used against the defendant.

The Fruit of the Poisonous Tree Doctrine in a DWI Case

The effects of an unlawful stop can extend beyond the stop itself. Under the fruit of the poisonous tree doctrine, evidence discovered as a result of unconstitutional police conduct may also be subject to suppression.

The basic idea is that if the initial police action is unlawful, evidence obtained because of that unlawful action may be considered the “fruit” of the original constitutional violation.

For example, suppose an officer stops a vehicle without reasonable suspicion. Only after making the stop does the officer claim to smell alcohol, ask the driver how much they drank, conduct field sobriety tests, arrest the driver, and obtain an Alcotest reading.

If the initial stop is successfully challenged, the defense may argue that the evidence developed afterward should also be excluded because it flowed directly from the unlawful seizure.

There are exceptions to the exclusionary rule and the fruit-of-the-poisonous-tree doctrine, so suppression is not automatic in every case. But when virtually all of the State’s DWI evidence developed only because of an unconstitutional stop, the legality of that first police action can become one of the most important issues in the entire prosecution.

Reviewing Police Reports, Dash Camera and Body Camera Evidence

The officer’s written report is only one version of what happened during the traffic stop.

A DWI defense attorney should compare that report against available objective evidence, including dash-camera footage, body-worn camera recordings, dispatch
audio, CAD records, photographs, and other records.

For example, an officer may write that the driver:

  • Weaved significantly
  • Crossed lane markings repeatedly
  • Appeared confused
  • Struggled to retrieve documents
  • Had difficulty exiting the vehicle
  • Displayed obvious signs of intoxication

Video may confirm those observations. It may also show that the actual events were less significant than the report suggests.

These inconsistencies can become important when challenging the legality of the stop, the officer’s credibility, probable cause for arrest, or the State’s overall DWI case.  See our statewide guide to challenging police reports using body-camera footage.

What About Statements Made During the Traffic Stop?

Statements made by the driver can create a separate defense issue.

Officers commonly ask questions such as:

  • “Where are you coming from?”
  • “Have you been drinking?”
  • “How many drinks did you have?”
  • “When was your last drink?”
  • “Were you driving the vehicle?”

Not every roadside question requires Miranda warnings. Miranda generally becomes an issue when a person is subjected to custodial interrogation.

The timing, location, nature of the questioning, whether the person was free to leave, and other circumstances can therefore become important when evaluating
whether a statement is admissible. Statements can sometimes be challenged separately from the legality of the traffic stop itself. For more information, see our guide to Miranda rights violations and coerced statements in New Jersey.

Can a DWI Be Dismissed After an Illegal Traffic Stop?

Potentially.

If the court suppresses evidence obtained after an unlawful stop, the next question is whether the State has enough independent admissible evidence remaining to prove the DWI charge.

In many traffic-stop DWI cases, nearly all of the evidence of intoxication develops after the vehicle has been stopped. That may include the odor of alcohol, admissions, balance observations, field sobriety tests, arrest observations, and breath-test evidence.

If those items are suppressed, the State’s ability to prove the case may be substantially weakened.

Suppression does not technically guarantee dismissal. The result depends on what admissible evidence remains after the court’s ruling.

The Traffic Stop Is Only the Beginning of the DWI Investigation

Even when the original traffic stop was lawful, other parts of a New Jersey DWI case can still be challenged.

Potential defense issues can include:

  • Improperly administered field sobriety tests
  • Medical or physical conditions affecting roadside performance
  • Breath-test calibration and operator procedures
  • Blood and urine collection procedures
  • Chain of custody problems
  • Proof of actual or intended operation
  • Drug Recognition Expert evaluations
  • Toxicology evidence
  • Statements made to police
  • Police video that contradicts the written report

When scientific or physical evidence is involved, the defense may also need to examine how that evidence was collected, preserved, transferred, and tested. See our Chain of Custody & Evidence Audits in New Jersey for a broader explanation of those issues.

Other New Jersey DWI Defense Strategies

A traffic-stop challenge is only one potential defense strategy. Depending on the facts of the case, constitutional violations, evidence problems, police-video issues, statements, forensic evidence, and other weaknesses may also affect the prosecution. For a broader overview, visit our Criminal Defense Strategies & Legal Tactics: A Statewide NJ Resource. Challenging the legality of the traffic stop is only one part of a New Jersey DWI defense. Other issues may involve field sobriety testing, breath-test evidence, proof of operation, medical conditions, blood or urine testing, drug-impairment evidence, and the penalties that apply after a conviction. For a complete overview of New Jersey DWI law and your potential defenses, contact one of our New Jersey DWI attorneys today for a free consultation.

Frequently Asked Questions About Challenging a DWI Traffic Stop

Can police stop me just because they think I may be drunk?

Police generally need an objectively reasonable factual basis for stopping the vehicle. That may come from an observed motor vehicle violation, reliable information suggesting dangerous or impaired driving, or another legally recognized basis for police intervention.

Does the officer have to prove I actually committed the traffic violation?

Not necessarily. The issue at a suppression hearing is usually whether the officer had reasonable and articulable suspicion to believe a violation occurred at the time of the stop. That is different from proving the traffic offense beyond a reasonable doubt.

Is weaving within my own lane enough for police to stop me?

Not automatically. New Jersey appellate decisions have recognized that weaving within a single lane is not itself the same as failing to maintain a lane. But repeated or unusual weaving, especially when combined with other circumstances, may still provide an objectively reasonable basis for police intervention.

Can a police officer stop me based on a misunderstanding of the traffic law?

It depends on the nature of the mistake. In State v. Puzio, the Appellate Division invalidated a stop based on an officer’s erroneous interpretation of a motor vehicle statute. Later cases have further addressed when an objectively reasonable mistake of law may nevertheless support a stop.

Can an anonymous 911 call lead to a DWI stop?

Yes, under appropriate circumstances. In State v. Golotta, the New Jersey Supreme Court upheld a stop based on a contemporaneous 911 report of dangerous and erratic driving. The reliability and detail of the information provided by the caller remain important.

What is a motion to suppress?

A motion to suppress asks the court to exclude evidence obtained through an unconstitutional search or seizure. In a DWI case, that can include a challenge to the original traffic stop and evidence obtained afterward. Read more about motions to suppress evidence in New Jersey.

What does “fruit of the poisonous tree” mean?

The phrase refers to evidence obtained as a result of earlier unconstitutional police conduct. If the original traffic stop was unlawful, the defense may argue that evidence developed because of that stop should also be excluded. Learn more about the fruit of the poisonous tree doctrine.

Can body-camera or dash-camera footage help challenge the stop?

Yes. Video can be used to compare the officer’s written description of the driving with what actually occurred. Differences between the report and the recording can become important at a suppression hearing or trial. See our guide to using body-camera footage to challenge police reports.

Challenging a DWI Traffic Stop in New Jersey

The traffic stop is the foundation of many New Jersey DWI prosecutions. If that foundation was unlawful, evidence developed afterward may be vulnerable to suppression.

William Proetta Criminal Law reviews police reports, dash-camera and body-camera footage, motor vehicle summonses, dispatch records, 911 recordings, CAD records, and the circumstances surrounding the stop to determine whether police had a legally sufficient reason to detain the driver. We also evaluate the other stages of the DWI investigation, including field sobriety testing, breath-test evidence, statements, proof of operation, and chemical testing.

If you have been charged with DWI in New Jersey, call (201) 793-8018 in Jersey City law office or (732) 659-9600 in Edison law office for a confidential consultation.