What Signs of Intoxication Do Police Look for When Justifying a Traffic Stop?

In order to make a traffic stop, police officers need to have reasonable suspicion that a crime is taking place. They are not legally allowed to pull someone over without reason to fish for possible crimes. 

Since that exact scenario does happen, the average person needs to understand what does and does not constitute reasonable suspicion. If they are pulled over without a justifiable reason, they may be able to have their charges reduced or their case thrown out with the help of a Pennsylvania DUI defense lawyer. This can be possible even if there happens to be strong evidence that they were committing a DUI.

Below are examples of some typical reasons why an officer might suspect that you’re driving impaired. While this list isn’t comprehensive, it shows you the type of decisions police officers need to make to have their arrest lead to a conviction.

If you have any questions about your rights as a driver, whether or not your stop was justified, or what strategies you can use to defend against your DUI charges, contact Steven E. Kellis for a free consultation. Call (267) 314-6693 or contact us online to schedule your free, no-obligation case review now.

Justifying a Police Stop When Traffic Laws Are Violated

Police are allowed to make judgment calls when weighing reasonable suspicion. Making judgment calls means they are permitted to make a stop even if they don’t witness a crime being committed. 

However, if they can say that they observed a crime in progress, their decision will face less scrutiny during prosecution. Because of this, observing a traffic violation is one of the most common reasons that a DUI stop occurs.

Examples of common traffic violations a police officer might observe before suspecting DUI include:

  • Crossing double yellow lines into the opposing traffic lane
  • Exceeding the posted speed limit
  • Failing to obey traffic device, i.e.: rolling through a stop sign or ignoring a red light
  • Pulling your vehicle into a crosswalk or past the line marker at an intersection stop
  • Failing to use turn signals (illegal in Pennsylvania)
  • Obstructing the roadway
  • Colliding with another vehicle or object (not technically illegal, but this will always lead to a stop)
  • Going the wrong way down a one way
  • Making an illegal turn
  • Crossing into the wrong lane when turning
  • Driving without headlights on at night
  • Driving 10 mph or more under the speed limit

Justifying a Police Stop By Saying the Suspect Was “Less Safe”

Instead of or in addition to justifying their reasonable suspicion by observing a possible crime, police can also allege that the vehicle operator was exhibiting driving behaviors that were clearly “less safe.” These observations directly relate to a public safety need, so they can provide a strong piece of evidence for prosecutors to use. 

On the other hand, police can make mistakes in judgment or material fact that show that the determination that someone was being “less safe” was not factually true beyond a reasonable doubt.

Examples of “less safe” driving behaviors that can lead to a police traffic stop include:

  • Swerving within your lane
  • Taking turns that are too wide or too narrow
  • Near misses with a vehicle or object
  • Driving too closely
  • Braking erratically
  • Taking too long to stop
  • Taking too long to resume driving from a stop
  • Accelerating aggressively
  • Reckless driving (technically illegal, but based on highly subjective judgments)
  • Drifting or doing burnouts
  • Unusual signaling
  • Driving while distracted (can sometimes constitute a traffic violation)
  • Driving off the roadway

Again, any of these acts can be seen by a jury or judge as understandably dangerous. However, they do not represent a binary “legal or illegal?” decision, so there’s more room for errors in judgment. With the right proof, such as dashboard camera footage, a DUI defendant may be able to establish that the officer’s account was flawed.

Subjective Observations Police Officers Use to Justify a DUI Stop

The final category of justifications for “reasonable suspicion” of DUI are incredibly subjective and often vague. None of them constitute a technical crime, nor do they necessarily indicate an action that was likely to lead to immediate harm. 

Because of these weaknesses, a police officer will usually want to list more than the observations in this category to justify reasonable suspicion for a DUI stop and probable cause for a DUI arrest. 

Without any sort of objective evidence to back up a vague or unprovable observation, it can be very possible for a DUI defense lawyer in Pennsylvania to get a charge thrown out because of a violation of due process. While this isn’t a guarantee of results it does mean that certain alleged “offenses” listed in a DUI arrest report should raise red flags.

Weak evidence used to justify DUI stops and arrests include:

  • Erratic driver behavior, such as singing or yelling out the windows (can sometimes constitute a crime, but usually only in extreme cases)
  • Failure to maintain lane
  • Drifting in lane
  • Varying driving speeds
  • Driving with face too close to the windshield
  • Appearing to be drowsy
  • Appearing to be distracted
  • And, the granddaddy of all vague reasons: “Suspect appeared to be intoxicated

All of these commonly find their way into DUI arrest reports and prosecutorial testimony. When you hear any of these phrases, ask yourself, “How can this possibly be proven?”, and, “How does this observation automatically mean the suspect was intoxicated?” These are questions that can be asked to juries. They can also be raised during motions intended to defend against frivolous and unfounded DUI charges.

Again, none of this means your DUI charges will automatically be thrown out. But part of a DUI defense attorney’s job is calling officers on vagueness and demanding that they explain why they think something subjective deserves to be evidence in a criminal proceeding.

Defend Against DUI with a Pennsylvania Criminal Defense Lawyer

Steven E. Kellis has handled countless DUI cases in his 25 years of experience. Many involve stops that were completely illegal or unjustified. It’s an unfortunate fact that individuals aren’t informed of their rights and end up pleading guilty to or confessing to DUI charges built upon an extremely flimsy case.

You can review the reasons for your arrest and see what defenses could be available in response during a free, no-obligation consultation with a Pennsylvania DUI lawyer near you. Simply call (267) 314-6693 or contact us online to schedule your free case review now.