What Is Probable Cause in a Maryland DUI Stop?

If you’re stopped by police in Maryland on suspicion of driving under the influence (DUI), the legality of that stop and any resulting arrest hinges on a crucial legal concept: probable cause. Understanding what constitutes probable cause in the context of a DUI case can help you protect your rights and challenge an unlawful arrest.

What Does “Probable Cause” Mean?

Probable cause is the legal standard that allows a police officer to make an arrest, conduct a search, or obtain a warrant. In DUI cases, it refers to the officer’s reasonable belief-based on observable facts and circumstances-that a driver is impaired.

The requirement for probable cause is rooted in the Fourth Amendment to the U.S. Constitution, which protects individuals from unreasonable searches and seizures.

How Probable Cause Applies to DUI Stops

There are two stages where probable cause plays a role in DUI enforcement:

1. The Initial Stop

Police need at least reasonable suspicion-a lower standard than probable cause-to initiate a traffic stop. This may be based on things like:

Swerving or erratic driving
Speeding or other traffic violations
Reports from other drivers

Once the vehicle is lawfully stopped, the officer must develop probable cause before making an arrest for DUI.

2. The DUI Arrest

To arrest someone for DUI, the officer must observe specific indicators of impairment, such as:

Odor of alcohol or marijuana
Slurred speech
Bloodshot eyes
Admission of drinking
Refusal to perform field sobriety tests
Poor performance on standardized field sobriety tests

In Court the officer may not rely on preliminary breath test results to establish probable cause.

Challenging Probable Cause in Court

An experienced DUI attorney can challenge the officer’s probable cause by:

Showing the officer lacked a valid reason for the initial stop
Arguing that signs of impairment were due to fatigue, illness, or anxiety
Contesting the reliability of field sobriety or breath test results

If the arrest lacked probable cause, your attorney can file a motion to suppress evidence. This could lead to the dismissal of your case.

Why Probable Cause Matters

If a court finds that your arrest was made without probable cause, any evidence obtained afterward-including breath or blood test results-may be inadmissible in court. That can significantly weaken the prosecution’s case.

Work with a Maryland DUI Attorney

Probable cause is often the first battleground in a DUI defense. At FrizWoods, we examine every detail of your traffic stop and arrest to determine whether your constitutional rights were violated.

If you’re facing a DUI charge, contact us today to schedule a consultation. We’ll review the evidence, explain your options, and fight for the best possible outcome.

FAQs

Q: Can I be arrested for DUI without a breath test?

A: Yes, if the officer has probable cause based on other signs of impairment, an arrest can be made without a chemical test.

Q: What if the officer never saw me driving?

A: Without direct observation of driving, probable cause becomes more difficult to establish, but it’s still possible depending on the circumstances.

Q: Can I challenge probable cause even if I failed sobriety tests?

A: Yes. Field sobriety tests are subjective, and their validity can be contested in court.

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