Every case is different. But this article discusses some of the more common features of DUI arrests and investigations.
In most DUI cases, police pull the motorist over because of signs of impairment (such as swerving) or a traffic violation (even something minor like a broken taillight will suffice). Generally, a stop is legal so long as police had reasonable cause (sometimes called “reasonable suspicion”) to believe the driver violated the law. (Read more about the legality of traffic detentions.)
If the police truly had no reasonable cause to pull you over, later in your case you can bring a motion to suppress, which can result in the entire case being thrown out.
Traffic detentions typically begin with the officer asking for your license and registration. The officer is likely to take note if, during this interaction, you show signs of impairment—things like fumbling around with your documents or the odor of alcohol or marijuana. Any such observations will undoubtedly show up in the police report, which you’ll typically see for the first time at your arraignment.
During a DUI stop, police almost always ask the driver if they’ve had anything to drink. In response, most motorists say something like, "just a beer or two with dinner"—usually an underestimation of what they actually drank. Police, having heard these types of responses innumerable times, aren’t likely to stop there—especially if there are other indicators that you’re drunk or have been using drugs. After receiving confirmation that you’ve been drinking—whatever the amount—most cops are going to want to investigate further. (Learn about the right to remain silent in response to police questioning.)
Generally, if police have probable cause to believe there’s incriminating evidence inside your car, they can search it without a warrant. For instance, an officer might see or smells things during a DUI stop that give them reason to suspect there are drugs in the car. If that’s the case, police could be justified in not only searching the interior of your car, but also the glove box, trunk, and closed containers such as backpacks. Another common justification for an automobile search is driver consent: Generally, police can look inside your car if you give them permission to do so.
(To find more about when police can search a car, see Can the Police Search My Car?)
An officer who suspects someone of drunk driving will often seek to confirm the suspicions using some roadside tests: field sobriety tests (FSTs) and a “preliminary alcohol screening” (PAS) test (commonly called a breathalyzer). These prearrest tests are typically voluntary.
There are lots of different FSTs that police use. But the most common are the three “standardized” FSTs, the:
In the 1970s, the National Highway Traffic Safety Administration (NHTSA) developed these three tests—which together are called the “standardized FST battery”—for officers to gauge a motorist’s level of impairment. After conducting studies, the NHTSA concluded the standardized FSTs were reliable indicators of when a driver’s blood alcohol concentration (BAC) is .1% or above.
A PAS device (also called “portable breath test” (PBT) machine) is a handheld machine that police use to measure a driver's breath alcohol concentration. PAS results are sometimes less reliable than breath or blood tests conducted at a police station or hospital. But the advantage of these devices is that they give police a quick and easy way to estimate a driver’s BAC. The purpose of a PAS test is not to gather evidence for court, but to assess whether there’s probable cause for a DUI arrest.
Most people are curious to see the DUI police report, which describes in the officer’s words what happened. In most states, the police report isn’t available until your first day in court, the arraignment. Because the report describes the case against you, it’s an important tool for deciding how best to handle your case. An experienced DUI attorney can often identify the strengths and weaknesses of the state’s case by reviewing the police report.
All 50 states have “implied consent” laws that require motorists lawfully arrested for DUI to submit to chemical testing. The purpose of the testing—usually of the breath or blood—is to measure the amount of drugs or alcohol in the driver’s system. Motorists who refuse testing normally face consequences that can include:
And if the case goes to trial, the prosecution can normally tell the jury about the defendant’s refusal. In some states, you can even be convicted of a separate crime for refusing a chemical test. In these states, a refusal can lead to two separate criminal convictions: one for DUI, and another for the refusal. However, in 2016, the U.S. Supreme Court held that laws criminalizing refusal to take a blood test were unconstitutional. But the Court did say that it's generally okay for a law to criminalize refusing to submit to a breath test. (To read more about the Supreme Court's decision, see DUI Testing: Breath, Blood, and Warrants.)
If police determine there’s probable cause to arrest you for driving under the influence, you’ll likely be cuffed and taken to the local jail or police station. When police arrest for a DUI, they typically take your driver’s license and give you a temporary paper driving permit. The temporary permit is normally effective until the court or department of motor vehicles makes a decision on whether to suspend your license. At the jail or police station, police will book and cite you for the offense. You’ll normally stay in jail until someone bails you out or a judge releases you on your “own recognizance.” If you were arrested on a Friday, and not bailed out, you might have to spend the entire weekend in jail. The good news is that you'll get credit against any future sentence imposed for time you’ve already spent in jail.
If you’ve been arrested for driving under the influence, it’s a good idea to get in contact with an experienced DUI attorney. DUI laws vary by state, and the facts of every case are different. A qualified DUI lawyer can help you understand what the law is in your state and explained any possible defenses you might have.