Whether Probable Cause for Arrest Exists in DUI Cases

Our attorneys know Virginia law and will protect your rights

Determining whether probable cause existed for an arrest in a DUI matter is an extremely important issue. In a DUI case, the arresting officer needs to establish probable cause that the driver of the vehicle is impaired either by alcohol or some other substance. The substance itself does not necessarily need to be illegal and can include such things as prescription drugs.

If there was no probable cause for the arrest, then the entire case may be dismissed. That’s why it’s so important to have an experienced DUI defense attorney who knows the legal standards the police must meet and can use those standards to your advantage. Contact Welch & Wright, PLLC today for a free consultation.

Evidence police use to determine probable cause

Driving behavior

The first thing a police officer can use is the driving behavior of the driver. A lot of the time, the police officer observes the bad driving behavior personally. Legal issues may arise if they did not see it themselves, for example, if some third-party witness calls it in. The driving behavior can prove both the reasonable suspicion to stop the vehicle as well as probable cause to arrest the driver. Speeding, swerving, disobeying traffic signs and signals are just a few common driving behaviors that can count towards the probable cause for arrest.

Demeanor and appearance of the driver

The officer can also take into account the demeanor of the driver after the stop. Does the driver admit to drinking alcohol? Does the driver have slurred speech? Are their eyes bloodshot? Does their motor function or movement seem impaired? Is the person nervous? The police officer can also consider other simple observations like the presence of open containers in the car and whether or not the driver smells like they have been consuming alcoholic beverages recently.

The most damning of these is the defendant’s own statement that they have been drinking. Many people claim to have only had “a couple drinks” but that alone can be enough for a judge to find probable cause for a valid arrest.

Field sobriety test

Field sobriety tests are most often used by police officers to determine whether or not probable cause exists. These tests are meant to determine (with varying degrees of validity) whether someone is impaired. These tests can be either standardized or unstandardized. The unstandardized tests lack a scientific basis for reliability, meaning they have not been tested under lab conditions and may not be reliable. These tests may be challenged as invalid by a skilled attorney in court.

Standardized tests have been subjected to lab conditions and have been scientifically examined for their reliability. These tests have been reviewed by the National Highway Traffic and Safety Administration (NHTSA) and are well regarded by almost all judges. These tests include the “9 step walk and turn,” “the one leg stand,” and the Horizontal Gaze Nystagmus (HGN). Although these tests are considered “reliable” indicators of someone’s impairment, a skilled attorney can challenge even these tests. The police officer observes how the driver does on these tests noting whether or not the driver exhibits “clues” of impairment. The attorneys at Welch & Wright are well versed in these standardized tests and have successfully challenged their validity in court.

Refusing to do the field sobriety test is not enough by itself to establish probable cause. However, it is a factor that can be taken into consideration and can be deemed circumstantial evidence that the driver is impaired.

Preliminary breath test

Under Va. Code 18.2-267(F), the law enforcement officer is required to inform a driver stopped for a suspected DUI that they have a right to take a Preliminary Breath Test (PBT). This breath test is usually performed by an Alka-Sensor, which is a small handheld device that the driver blows into to determine the driver’s probable Blood Alcohol Content (BAC) at that time. These machines are not nearly as accurate as establishing someone’s actual Blood Alcohol Content like the Intox EC/IR II breath machine at the police station or a blood draw. However, they are deemed accurate enough to establish probable cause to arrest.

There is technically no required level of BAC that the driver has to reach on the PBT to establish probable cause. However, the presumptive level of intoxication in Virginia is .08. So, this number has become almost a de facto limit to establish probable cause to arrest a driver for a DUI.

If the police didn’t have probable cause to arrest you, we can help

If the police don’t have probable cause to arrest you, then your DUI charges can most likely be dismissed. However, you need the right attorney to show that their actions didn’t meet the probable cause standard. This is a tricky, highly technical line of argument that needs to be made by an experienced DUI defense lawyer. If you were arrested for DUI in Norfolk, Virginia Beach, or any other jurisdiction in the Hampton Roads area, give us a call or contact us online today to find out how we can protect your rights.