Reasonable Suspicion for a DUI Stop

Generally, police officers are not allowed to stop or detain drivers without cause. The officer must have reasonable suspicion that the driver committed a crime. For drunk driving cases, law enforcement officers may pull people over if there is a reasonable suspicion the driver is drunk or committed a traffic offense. Reasonable suspicion generally requires specific facts together with reasonable suspicion. The police can’t stop a driver based on “a hunch.”

Once police make a traffic stop, they can temporarily detain the driver for a brief investigation, which could include conducting field sobriety tests or a breath test. If the officer has probable cause to believe the driver is impaired, the driver may be arrested and taken to jail.

Signs of Driving Under the Influence

Based on police training and experience, police officers look for certain signs that you are under the influence of drugs, alcohol, or a combination of alcohol and drugs. Evidence of impairment may include:

  • Driving noticeably slower than the speed limit or other motorists
  • Erratic driving, such as swerving or delayed response to traffic signals
  • Straddling the centerline or drifting between lanes
  • Near misses of other cars or objects
  • Illegal turns or failure to obey traffic signals
  • Braking frequently or stopping in a lane of traffic for no apparent reason

Vehicle Violations and Traffic Stops

Police officers can initiate a traffic stop for just about any vehicle violation. It is not uncommon for police to wait near bars or entertainment districts around closing time and pull over drivers for even the most minor violations. Minor traffic violations that could be elevated to a drunk driving investigation may include:

  • Improper lane change
  • Failure to signal
  • Tinted window infractions
  • Driving without headlights on
  • Expired registration
  • Broken tail light
  • Seatbelt violation
  • Texting and driving

Once the driver is stopped, the officer may look for other signs of impairment. Indications that the driver may have been drinking alcohol or taking drugs may include:

  • The smell of alcohol on a driver’s breath
  • An alcoholic beverage container in the vehicle
  • Drug paraphernalia in plain view
  • Slurred speech
  • Driver admitting to having a couple of drinks
  • Inconsistent stories about where they were coming from or going to

Sobriety Checkpoints

Sobriety checkpoints are an exception to the reasonable suspicion requirement. Many states and cities use DUI checkpoints to deter drivers from driving drunk, knowing there is a risk they could be stopped even if they are not breaking any other traffic law. To have the proper deterrent effect, many police departments publicly state where and when the sobriety checkpoint will take place ahead of time.

Some states have banned drunk driving checkpoints, and courts in others have found them to violate the state constitution. However, the U.S. Supreme Court has found DUI checkpoints to be valid as an “administrative procedure,” even if there is no reasonable suspicion the driver was breaking the law.

Reasonable Suspicion vs. Probable Cause

Police officers do not necessarily need hard evidence of a crime or proof of criminal activity. Instead, the officer needs enough information that would lead a reasonable person to suspect that a person is committing, has committed, or is about to commit a crime. Reasonable suspicion has a lower burden of proof than probable cause. Probable cause requires information or evidence that a reasonable person would believe a crime was being committed or going to be committed.

An officer who has such a reasonable suspicion generally has the right to temporarily stop drivers to investigate. However, reasonable suspicion may not be enough to take the driver into custody or detain the driver any longer than necessary. If the police want to arrest the driver, they generally need probable cause.

Probable cause that a driver is driving drunk is generally gathered from the interaction with the driver during the traffic stop. This includes signs of impairment, statements from the driver, and field evidence. Field evidence during a traffic stop may include a breath test and field sobriety tests.

The police may ask the driver to submit to a Breathalyzer test. This portable breath sample test will give an estimate of the driver’s blood alcohol content (BAC). In most states, drivers can refuse a roadside breath test without consequences. After a DUI arrest, the driver may be required to submit a blood alcohol level test or face a mandatory license suspension.

Getting Stopped Without Reasonable Suspicion

If you are stopped without reasonable suspicion, what are your rights? If the police officer makes a drunk driving stop without any specific facts or articulable suspicion of a crime, the police may have violated your constitutional rights against unreasonable search and seizure. Your criminal defense lawyer can use this as a reason to have any evidence of alcohol suppressed, or kept out of court. If the judge grants a motion to suppress evidence, the prosecutor will not be able to use any direct evidence gathered as a result of the illegal traffic stop.

If you have been pulled over for a DUI and the police officer did not have reasonable suspicion that you have committed a crime, an experienced lawyer could have the evidence against you thrown out. A drunk driving lawyer could also help you build a strong legal defense against DUI charges or negotiate a plea deal to reduce your sentence. Ask your criminal defense attorney about the best legal defense strategy in your case.

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