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What is Probable Cause and How Does it Affect My DWI Case?

The Constitution provides each person in the United States with certain rights. The Fourth Amendment to the Constitution protects your right to be free from unreasonable searches and seizures. This means that the police cannot search or detain you, your home, or your vehicle without a very good reason. This reason is known as "probable cause."

Probable cause can be incredibly important to your Houston criminal DWI case. Why? Police must have probable cause before (a) searching you or your vehicle and (b) making a DWI arrest. Searches, seizures, and arrests made in the absence of probable cause can be invalidated. Evidence that is obtained in violation of your rights can be suppressed. Without evidence to support its case against you, the state may be forced to drop the DWI charges altogether.

What Is Probable Cause?

The Fourth Amendment explains that

the right of the people to be secure in their persons, houses, papers, and effects, against unreasonable searches and seizures, shall not be violated.

It expands on this protection by stating that

no Warrants shall issue but upon probable cause, supported by Oath or affirmation, and particularly describing the place to be searched, and the persons or things to be seized.

The Fourth Amendment, however, does not explain what exactly probable cause is. Since the authors of the Fourth Amendment didn't provide a definition, it was left to the courts to decide precisely what the standard of "probable cause" should be.

In 1949, the Supreme Court of the United States held that probable cause

exists where the facts and circumstances within the officers' knowledge, and of which they have reasonably trustworthy information, are sufficient in themselves to warrant a belief by a man of reasonable caution that a crime is being committed.

In other words: probable cause means that there is a reasonable belief, after considering relevant facts and circumstances, that a criminal act has been committed. However, it's important to note that probable cause must be based on more than a gut feeling or bare suspicion. The circumstances of the situation must support a suspicion of guilt.

How Probable Cause Affects Your DWI Case

In Texas, police must have probable cause to search your vehicle, administer a breath test or blood test, or make an arrest for DWI. If police lack probable cause for any of these things, the DWI charges against you can be invalidated. It is never appropriate for the state to violate your fundamental Constitutional rights without a valid reason. Those rights may only be infringed when the state has probable cause.

Do Officers Have to Get a Warrant During a DWI Stop?

It's always the best rule of thumb for police officers to obtain a warrant before performing a search or making an arrest. A warrant will only be authorized when that officer can provide probable cause for the search or arrest. As a result, most warranted searches and arrests will be upheld if they are challenged. However, police do not always have the luxury of time to secure a warrant. Unwarranted searches and arrests are generally permissible when officers have probable cause.

They can also be valid if police can cite exigent circumstances that made the immediate search or arrest necessary. Exigent circumstances mean that there is an immediate need to perform a search or make an arrest to protect the officers, protect the public, or prevent the destruction of evidence. In other words, making an unwarranted search or arrest protects the public interest.

Unwarranted Search Exception: Blood Tests

There are limits to when police can perform unwarranted searches during a DWI stop in Texas. In 2014, a Texas court held that the state's implied consent law was unconstitutional. Under the law, any driver who got behind the wheel was automatically presumed to have agreed to chemical testing if they were stopped for DWI. So, police could essentially force drivers to take a breath or blood test to gather evidence. It didn't matter if the driver objected; driving the vehicle triggered consent. The state court held that this practice violated the Fourth Amendment and a driver's right to be free from unreasonable searches.

Today, drivers in Texas have the right to refuse chemical testing. However, officers can still secure a sample of your blood with a search warrant. A warrant request must be based on probable cause and explain to a magistrate why the officer believes that you are intoxicated. Search warrants will only be issued when police can provide enough evidence to show that it is reasonable to believe you are intoxicated.

Factors and Circumstances That May Support Probable Cause

So, police officers can only perform a search, seize evidence, or make a DWI arrest if there is probable cause to support those actions. Probable cause is based on an objective evaluation of the facts and circumstances of the situation.

What facts and circumstances may support the existence of probable cause? See below.

Violating Traffic Law

Drivers who are not impaired should be able to understand and follow local traffic laws and customs. If an officer witnesses you speeding, rolling through stop signs, or breaking other traffic laws, they can use that information to support probable cause of intoxication. However, these factors, on their own, will likely be insufficient to support a DWI search or arrest.

Driving Recklessly

Driving a little bit over the speed limit and rolling through stop signs is one thing. Reckless and dangerous driving behaviors are another. Reckless driving behaviors that support probable cause in a DWI case include:

  • Driving the wrong way down a street
  • Weaving between lanes
  • Driving at dangerous speeds
  • Failing to stop at an intersection
  • Actively trying to evade police

These behaviors could suggest that a driver is intoxicated. Police could point to these things to prove that probable cause exists.

Odor of Drugs or Alcohol

The odor coming from a vehicle during a traffic stop could suggest that you have recently used drugs or alcohol or that those substances are present in the car. Police can use this as a basis for a search of the vehicle and more intensive investigation of possible DWI.

Drugs, Alcohol, or Paraphernalia in Plain View

It's never a good idea to drive with drugs, alcohol, or paraphernalia in plain view. If an officer views any of these items during a traffic stop, the officer will use it as evidence to support probable cause, a search of the vehicle, and a possible arrest.

Physical Behavior and Characteristics

Your physical characteristics and behavior during a traffic stop can be used to support probable cause of intoxication. Any of the following things could indicate to an officer that you are intoxicated:

  • Slurred speech
  • Inability to maintain eye contact
  • Difficulty staying awake
  • Confusion
  • Impaired motor function
  • Impaired balance or coordination

Attitude and Interaction With Police

Police officers will also assess your attitude and behavior during your interaction during the DWI stop. Officers may be inclined to believe that you are intoxicated if you are belligerent, uncooperative, or hostile.

Refusal to Take a Field Sobriety Tests

You don't have to agree to perform field sobriety tests. However, police can use the fact that you refused to cooperate to take the test to support probable cause for a DWI arrest. The fact that you take and fail a field sobriety test can also be used against you.

One of these factors, on its own, may be insufficient to establish probable cause. However, when viewed together, a finding of probable cause may exist. This is why police officers will generally point to a number of factors that support a reasonable belief that you have committed a crime.

What Happens If Police Don't Have Probable Cause During a DWI Stop?

Violations of your Constitutional rights can destroy a criminal DWI case against you. Under the exclusionary rule, any evidence or information that has been tainted by a violation of your rights can be suppressed. This means that your attorney can ask the court to prevent that evidence from being used against you. It can really handcuff the prosecution and prevent them from proving that you are guilty of DWI beyond a reasonable doubt. Evidence is crucial to a strong case.

Without evidence, the state can be forced to drop the criminal DWI charges. However, it is important to note that you can still face administrative penalties for DWI, even if criminal charges are unsuccessful. This means that you can be forced to pay expensive fines, install a breath device in your vehicle, and even lose your license for a period of time. It's always best to have an attorney help you navigate both the criminal and administrative aspects of a DWI.

Contact Our Houston DWI Defense Attorney for Probable Cause

Have you been arrested for DWI in Houston? Do you believe that police searched your vehicle or made an arrest without establishing probable cause? Contact the Doug Murphy Law Firm, P.C. at 713-229-8333 for immediate assistance with your defense.

Our experienced Houston DWI attorneys will review your case and aggressively fight criminal charges on your behalf. The state should not be allowed to benefit from an illegal search or arrest. We'll demand that the state be prohibited from using tainted evidence and ask for the charges against you to be dropped immediately. Call us today to schedule your free consultation and learn more.

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