Can Police Pull You Over Without Seeing a Traffic Violation?

Oct 30

Illegal Traffic Stops in Arizona

You see flashing lights in your rearview mirror. You pull over. The officer approaches your car, asks where you are coming from, and begins asking questions. Maybe the encounter eventually results in a DUI investigation, field sobriety tests, a blood draw, or even an arrest.

But there is an important question that comes before all of that:

Why did the police officer pull you over in the first place?

Police officers do not have unlimited authority to stop vehicles simply to see what they might find. A traffic stop is a seizure under the Fourth Amendment, which means the government generally must have an objectively reasonable basis for initiating the stop.

That can become an important issue in an Arizona DUI or criminal case. Even when police ultimately discover evidence of a crime, the defense may still examine whether officers had lawful grounds to initiate the traffic stop that led to that evidence.

At AJB Law Firm, LLC, Tucson criminal defense attorney Amanda Bynum evaluates not only what happened after a traffic stop, but also what the officer knew and observed before the emergency lights came on.

Do Police Need a Reason to Pull You Over in Arizona?

Yes. An officer generally needs an objectively reasonable legal basis to stop a vehicle.

An officer may initiate a traffic stop after observing a traffic violation. For example, an officer might observe a driver speeding, running a red light, failing to stop at a stop sign, or committing another violation of Arizona traffic law.

But an observed traffic violation is not the only possible justification for a stop.

An officer may also have reasonable suspicion that a crime has occurred or is occurring. Reasonable suspicion is a lower standard than probable cause, but it still requires more than an unsupported hunch. The officer must be able to identify particular facts that objectively support the suspicion.

This distinction matters.

An officer does not necessarily need to know with certainty that a driver committed a crime before making a stop. But the Fourth Amendment generally requires the officer to have articulable facts supporting the intrusion.

What Is “Reasonable Suspicion”?

Reasonable suspicion is one of those legal phrases that sounds simple until it has to be applied to actual facts.

Courts consider the totality of the circumstances rather than looking at one fact in isolation. An officer may rely on observations, information received from dispatch, reports from witnesses, and reasonable inferences based on the circumstances.

For example, depending on the circumstances, reasonable suspicion might be based on:

unusual driving behavior suggesting possible impairment;
a vehicle matching a sufficiently specific description connected to reported criminal activity;
observations suggesting the driver committed a traffic offense;
reliable information provided by another officer or witness; or
a combination of circumstances that objectively suggests criminal activity.

But there is an important limitation: reasonable suspicion must be based on facts, not merely a generalized feeling that something seems wrong.

That is why the precise circumstances leading up to a traffic stop can matter so much in a criminal case.

Does the Officer Have to Actually See a Traffic Violation?

Not necessarily.

There are circumstances in which police may lawfully stop a vehicle even though the stopping officer did not personally witness a traffic violation.

For example, an officer may receive information from another law enforcement officer or from dispatch. Police may also be responding to a report concerning suspected criminal activity.

But the existence of a report or dispatch call does not necessarily end the legal analysis. Depending on the case, questions may include:

Who provided the information?

What exactly was reported?

How specific was the description?

How reliable was the information?

Did the vehicle actually match the description?

What did the officer observe before initiating the stop?

How much time passed between the reported event and the stop?

Those details can determine whether there was an objective basis for stopping a particular vehicle.

What If the Officer Was Mistaken?

Traffic stops can also involve mistakes.

Sometimes an officer may misunderstand what a driver did. Other times, an officer may misunderstand what the law actually prohibits.

The Supreme Court has recognized that a reasonable mistake can, in some circumstances, still be consistent with the Fourth Amendment. But that does not mean every mistake automatically becomes reasonable merely because an officer made it.

The particular law, the officer's observations, and the objective reasonableness of the asserted justification may all matter.

This is one reason a defense attorney should look beyond a sentence in a police report stating something like, “I observed a traffic violation.”

What violation?

What exactly did the officer observe?

Does that conduct actually violate the statute the officer relied upon?

Those questions can make a significant difference.

The Police Report Is Not Necessarily the Whole Story

Imagine a police report stating:

“Vehicle was observed weaving, and a traffic stop was initiated.”

That description may sound incriminating, but it leaves important questions unanswered.

How much did the vehicle allegedly weave?

Did it cross a lane line?

How many times?

Over what distance?

What were the road conditions?

Was there construction?

Did video capture the driving?

What did the officer say in real time?

When exactly did the officer decide to initiate the stop?

A criminal defense investigation may involve comparing the officer's written description with other available evidence.

That can include:

body-worn camera footage;
dash-camera footage;
dispatch recordings;
CAD records;
911 calls;
photographs;
GPS or location information;
police radio communications;
witness statements; and
the applicable Arizona traffic statute.

The question is not simply what the officer later said justified the stop.

The question is what the evidence demonstrates the officer knew and observed when the seizure occurred.

Why Does the Reason for the Stop Matter in a DUI Case?

Consider a DUI investigation.

The traffic stop happens first.

Then the officer approaches the vehicle and may claim to smell alcohol. The officer asks questions. The driver may admit to drinking. The officer may observe allegedly bloodshot or watery eyes. The driver may be asked to perform field sobriety tests. A preliminary breath test may be administered. The driver may ultimately be arrested and subjected to breath or blood testing.

By the end of the investigation, the government may have accumulated substantial evidence.

But that evidence does not necessarily answer the threshold question of whether police had lawful grounds to initiate the stop.

The sequence matters.

The government generally cannot justify an earlier seizure solely by pointing to incriminating evidence discovered afterward.

That is why a defense attorney evaluating a DUI case may begin the analysis before the officer ever reaches the driver's window.

Can an Illegal Traffic Stop Get a DUI Case Dismissed?

Potentially, but suppression and dismissal are not the same thing.

When evidence is obtained as a result of an unconstitutional search or seizure, the defense may ask the court to suppress evidence obtained as a result of that violation.

This is commonly done through a motion to suppress.

If the defense challenges the legality of the stop, the court may hold an evidentiary hearing. The officer may testify about what was observed and why the vehicle was stopped. The defense may cross-examine the officer and use other evidence, including video or dispatch records, where appropriate.

If the judge concludes that the stop violated the Fourth Amendment, evidence obtained as a result of the unlawful seizure may potentially be excluded.

In a DUI case, that can be significant.

Depending on the circumstances, the challenged evidence could include observations made after the stop, statements by the driver, field sobriety testing, and evidence ultimately leading to chemical testing.

Suppression does not automatically mean every case will be dismissed. The effect depends on what evidence remains and what the prosecution must prove.

But in some cases, suppression can substantially weaken the prosecution's ability to proceed.

“What If I Really Was DUI?”

People sometimes assume that if their blood alcohol concentration was above the legal limit, there is no reason to examine the traffic stop.

That is not necessarily true.

Suppose an officer stops a vehicle without constitutionally sufficient justification and only afterward discovers evidence suggesting that the driver was impaired.

The evidence discovered later does not necessarily retroactively create reasonable suspicion for the earlier stop.

Think about the timeline:

What did the officer know before stopping the vehicle?

That question is different from:

What did the officer discover after stopping the vehicle?

The distinction is fundamental to Fourth Amendment analysis.

A high BAC result may be extremely important evidence in a DUI prosecution, but it does not eliminate the need to examine how the police encounter began.

Body-Worn and Dash-Camera Video Can Matter

Video evidence has changed the way many traffic-stop cases can be evaluated.

Historically, a defense attorney might have been left primarily comparing an officer's report with a client's recollection. Today, depending on the agency and circumstances, additional evidence may exist.

Video may show the officer's view before the stop. It may capture statements made immediately afterward. Dispatch records may establish what information the officer actually received. CAD records may help establish the timeline.

Sometimes that evidence confirms the police report.

Sometimes it provides additional context.

And sometimes it raises questions that are not apparent from reading the report alone.

For that reason, a thorough defense review should not necessarily stop with the officer's written narrative.

What Should a Defense Attorney Look for When Reviewing a Traffic Stop?

There is no single checklist that determines whether every traffic stop is constitutional. The facts of each case matter.

But some of the questions worth examining include:

What reason did the officer give for the stop?

What did the officer actually observe?

When did the officer observe it?

Does the alleged conduct actually violate Arizona law?

Is the officer's account consistent with available video?

Was the officer relying on information from someone else?

If so, what information was actually communicated?

Was there a sufficient basis to connect this particular vehicle or driver to suspected criminal activity?

Does the timeline support the government's explanation?

The defense can then compare those facts against the constitutional standard governing investigative traffic stops.

Challenging Traffic Stops in Tucson and Pima County

Traffic stops leading to DUI and criminal charges occur throughout Tucson and Pima County and may involve the Tucson Police Department, Pima County Sheriff's Department, Arizona Department of Public Safety, Oro Valley Police Department, Marana Police Department, or other law enforcement agencies.

The constitutional principles governing a traffic stop apply regardless of which agency conducted the investigation, but the evidence available in an individual case can vary considerably.

That is why reviewing the actual disclosure matters.

A criminal defense attorney may need to examine reports, video, dispatch information, chemical testing records, witness statements, and other evidence before determining whether there is a viable challenge to the stop.

Charged With DUI or Another Crime After a Traffic Stop in Tucson?

If you were arrested after a traffic stop, it can be tempting to focus exclusively on what happened at the end of the investigation.

What was my BAC?

How did I perform on the field sobriety tests?

What did I tell the officer?

What did the police find in the vehicle?

Those questions may matter. But a criminal defense attorney should also consider what happened at the very beginning.

Why were you stopped?

What did the officer know at that moment?

What evidence supports the officer's explanation?

And did those facts provide a constitutionally sufficient basis for the seizure?

At AJB Law Firm, LLC, attorney Amanda Bynum represents individuals charged with DUI and criminal offenses in Tucson and throughout Pima County. A careful defense begins with reviewing the evidence and identifying the legal and factual issues that may affect the prosecution's case.

If you have been charged with DUI or another criminal offense following a traffic stop, contact AJB Law Firm to schedule a consultation and discuss the circumstances of your case.

This article provides general information about Arizona criminal law and is not legal advice. Reading this article or contacting AJB Law Firm does not, by itself, create an attorney-client relationship. Every case is different, and the outcome of any legal matter depends on its particular facts and circumstances.