brian sloan profile picture

Debating the Merits of the Initial Police Stop: Was There Probable Cause?

For example, let’s start with the initial police stop. A police officer has to have a legitimate, legal reason to pull someone over. They can’t just pull people over without a valid reason. If they are pulling someone over for reasons such as a license plate light out, a cracked windshield, maybe weaving within your lane, or weaving outside your lane, then there is cause to pull you over. An officer can come up with a number of different reasons to pull someone over but that doesn’t mean that they can simply just launch into a DUI investigation.

The Police May Have Cause to Pull You Over But That Doesn’t Always Translate Into Cause to Begin a DUI Investigation

That’s an area that I’ve been focusing on for a little while now and I’ve been fairly successful in arguing that point. The issue becomes, did the officer unconstitutionally keep someone from going about his or her business? We do have the Fourth Amendment right to be free from illegal search and seizure.

An officer can pull someone over and talk to them and do an investigation, but in pulling over a vehicle, an officer constitutionally has to limit his investigation solely to the reason for the stop.

For example, if someone drove outside of the lane, that should not be an excuse for an officer to pull someone over. The first thing the officer shouldn’t say is, “Get out of the vehicle. We’re starting a DUI investigation.” There are many reasons that could cause someone to drive outside of their lane and the officer has to limit his contact with the person he’s pulled over solely for the reason for the stop.

The Police Must Have Reasonable Suspicion to Initiate a DUI Investigation

Interviewer: What is currently happening in your area? Is it that police will pull someone over and will they always say, “I can smell alcohol. Step out of the car.” Will they make up an excuse to take it to a DUI investigation? What literally happens during a stop that moves it from point A to point B?

Brian Sloan: That scenario does often occur. The officers, upon approaching a vehicle for a limited purpose such as crossing over a lane line or having a broken tail light, will then ask for a license, registration, insurance, which is fine, and then the officer will claim that they have developed new reasonable suspicion to investigate a new crime such as DUI.

This is because they noticed slurred speech on the person, because they smell the odor of alcohol coming from the person’s breath or inside their vehicle, or they notice bloodshot and water eyes. Then they are allowed to launch into a DUI investigation; however, there is a legal order to the process.

Legally, a Traffic Infraction Isn’t Probable Cause to Begin a DUI Investigation

An officer can’t just jump into a DUI investigation. The officer has to develop new reasonable suspicion above and beyond the reason for the stop. Sometimes the officer doesn’t do that. Sometimes the officer will pull someone over for a license plate light out, and the first thing they do is order the person out of the vehicle.

There’s no reason for a person to have to get out of a vehicle for a license plate light out. The officer has the option of ticketing the person or warning the person and letting them be on their way. That complies with the constitution. You limit the stop for the amount of time that is necessary to investigate the reason for the stop. If the officer ‘jumps the gun’ that can be a way in which all evidence can be suppressed against the person and basically results in a case being dismissed.

Interviewer: It’s seems like a ‘he said, she said’ type of situation. Can’t the police always just say, ‘Well, they said this, and they said that,’ and legitimize the stop? How do you defend that?

Some Arizona Police Department Are Equipped with Police Video Cameras

Brian Sloan: Unfortunately, in our system the officer is very likely going to be believed over the suspect, or the defendant. Unfortunately, not too many police agencies have video cameras. There are two exceptions. The Glendale Police Department, I believe has video cameras in all of their patrol vehicles and the ASU Police Department has video cameras in their patrol vehicles.

There was supposed to be 50 Phoenix police officers that received personal video cameras, which I believe are worn over their ear. It’s a product, I believe put out by Taser. It’s a personal video camera that goes over their ears.

By Brian Douglas Sloan

city view

Call me today for an
‘In Depth’ Free Consultation

brian sloan profile picture
Brian Douglas Sloan


aerial view of arizona
Best DUI Lawyer in Phoenix

Why DUI Attorney Brian Douglas Sloan?


19+ Years SOLELY Focused on DUI Defense


4,200+ DUIs Successfully Defended

Top Accolades

  • Only DUI "Power Lawyer" in the Nation Featured in USA Today, 2022

  • Top 10 in Arizona

Top 1%

Top One Percent in the Nation

Superb 10/10

4.9 / 5.0


brian sloan on the cover of attorney at law magazine

“I am one of only a handful of Phoenix DUI Lawyers that focuses solely on DUI Defense representation.”

I have spent my entire career focused on Arizona DUI Defense representation, having personally defended over 4,200+ DUI clients in the past 19+ years.

If you’re looking for a divorce attorney, tax attorney, or civil attorney, I can comfortably say, "I’m not the one for you."

Coming up with traditional, as well as outside-the-box motions and defenses for my clients, often with good results, is the hallmark of my practice.

Lawyers that say they are "aggressive" or "will fight for you" are a dime a dozen. They use these phrases because they think people want to hear them. Being "aggressive" isn’t the same as being good and is often used to put on a show to hide the fact that they aren’t doing anything meaningful for the client.

The same is true for the lawyers claiming to do DUI Defense, Criminal Cases, Accident Cases, and Divorces. A Jack-of-all-Trades is a master of none! By handling all sorts of cases, they take away from their ability to truly focus on DUIs, and keep up to date on the latest changes in Phoenix DUI Defense Representation.

What I offer is intelligent, quality DUI Defense at an exceptional price.

I have not only taught other lawyers how to do DUI Defense Representation at statewide seminars, but I produced DUI Legal Guides used by defense lawyers across Arizona.

I am one of Arizona's most award-winning DUI Defense Lawyers, recognized nationally, including in a 2022 issue of USA Today.

There are no other private DUI Defense Lawyers in Arizona that have personally defended more DUI cases than I have. And as a bonus, I offer a flat rate for my legal services without any hidden charges. This guarantees that I offer some of the most competitive rates among all Arizona DUI Attorneys, while being the preeminent leader in the field of DUI Defense Representation.

Over the years, countless people have come to me after discovering that their first lawyer made a mistake, gave them false hope or false promises, or simply took their money and didn't do much to advance their case. And you would be surprised at how often this happens.

So, instead of wasting time and money on the wrong DUI Defense Attorney, do yourself a favor and get the proven and documented best DUI Lawyer in Phoenix and the surrounding areas of Maricopa County.

You can reach me on my cell phone: 480-720-7839.

dui attorney brian sloan headshot

Brian Douglas Sloan

DUI Attorney

Free Initial

small mail icon
Email address:
small location icon
2 N. Central Ave Suite 1929
Phoenix, AZ 85004
triangle pattern