Virginia police officer giving field sobriety tests trying to establish probable causeMany people believe there is nothing they can do but plead guilty after being arrested for driving under the influence (DUI) in Northern Virginia. However, this is not true. If the police charge you with DUI, you may have strong defenses, that can result in the charges being dismissed or reduced to a much less serious offense, even if you think the police have enough evidence to prove their case against you. One such defense is that the police lacked probable cause to arrest you. An experienced Virginia DUI attorney can help identify and prove this and other defenses.

Probable cause is the second lowest legal standard. It requires a police officer to have enough information immediately prior to the arrest to probably believe that the person committed the offense for which he is being arrested. For a DUI charge, the police must have enough evidence to reasonably believe the person being arrested was the driver of the vehicle, operated that vehicle on a Virginia road, and was under the influence of drugs or alcohol at the time of operation. In reviewing whether police have probable cause for an arrest, courts review the "totality of the circumstances" known to the officer immediately before the arrest is made.

To aid in the detection of DUIs, the National Highway Traffic Safety Administration (NHTSA), a federal agency, has created numerous tests and factors for police to be on the lookout for to identify intoxicated drivers. NHTSA's factors are taught to nearly every police officer through their local training courses as well as national courses. Below are some of the most common facts and circumstances that police rely on to establish probable cause for a DUI arrest.

Driving Behaviors Used to Establish Probable Cause for the Police to Charge You with DUI in Northern Virginia

Erratic driving behavior is usually the first thing an officer can observe in a suspected DUI. Erratic driving includes the following driving behaviors:

  • Lane position. If you are having problems maintaining proper lane position, this may help establish probable cause. Examples of this include weaving, swerving, being in two lanes, and taking turns too widely.
  • Speed and brakes. Stopping too far from a curve, parking at an abnormal angle, stopping suddenly, stopping past the traffic line at an intersection, and driving too slowly or too quickly are some of the speed and brake issues that may be used to justify you being pulled over.
  • Vigilance. Driving in the wrong lane or wrong direction on the street, not using headlights and/or windshield wipers, running a light or stop sign, and improper use of signals are some vigilance problems that an officer may observe.
  • Errors in judgment. Errors in judgment might also lead to a stop and DUI investigation. Tailgating another vehicle, making unsafe lane changes, or driving off the road are just a few judgment mistakes that can lead to an investigative stop.

Another way that the police can establish probable cause to arrest you for DUI is if you make statements about consuming alcohol. Even saying you had only one or two drinks several hours earlier can be enough for police to have probable cause for a DUI arrest. Rather than lying or incriminating yourself, you should inform the officer that you do not wish to make any statements. Invocation of your Fifth Amendment right to silence cannot be used against you in court.

Appearing Intoxicated May Also Be Considered When Determining Whether There Is Probable Cause for a DUI Arrest

If you appear intoxicated, this may be the basis of probable cause to arrest you. Glassy or bloodshot eyes, slurred speech, being unsteady on your feet when standing or walking, and an odor of alcohol on your breath can be considered signs that you are intoxicated, thereby justifying an arrest for DUI.

Field Sobriety Tests Used to Establish Probable Cause

Field sobriety tests (often referred to as FSTs) are a common tool used by the police to establish probable cause to charge someone with DUI.  FSTs are divided attention tests because they require you to balance physical tasks with mental tasks. There can be a number of defenses to the results of field sobriety tests, including the way that they are administered by the officer. Common field sobriety tests used in Virginia include:

  • Walk-and-Turn. This test requires a person to walk nine steps in a straight line heel-to-toe and then turn around and do it again.
  • One Leg Stand. A person performing this test must hold his leg out six inches off the ground while counting until the officer tells him to stop.
  • Horizontal Gaze Nystagmus (HGN). The Horizontal Gaze Nystagmus tests a driver’s eyes as they move side to side. It can detect an involuntary jerking of the person’s eyes, which is a sign of intoxication. This test is not accepted by all Northern Virginia courts for purposes of showing intoxication due to the medical expertise required to observe and analyze a person's nystagmus (side-to-side movement of the eyes).

Preliminary Breath Tests and Probable Cause in Fairfax DUI Cases

The preliminary breath test (PBT) is a breath test taken when an individual is stopped for DUI to measure his blood alcohol content (BAC). If the test indicates the presence of alcohol, the police may have probable cause to arrest a person at that point, even if there was no bad driving or any FSTs indicating intoxication.

It is important to know, however, that the PBT is completely voluntary. A driver can refuse to take this test without any negative consequences to them or their case. As with field sobriety tests, there are many ways to challenge preliminary breath test results—and the probable cause required to arrest you.

Were you arrested for DUI in Northern Virginia? You need an experienced Fairfax DUI lawyer to obtain the best possible outcome. Our skilled DUI attorneys have decades of experience defending clients facing drunk driving charges in Fairfax and throughout Northern Virginia. To learn how we can assist you, start an online chat today to schedule your free consultation.