How a DUI Is Proven

Understand the elements of a DUI

By Canaan Suitt, J.D. | Last updated on August 4, 2022

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Depending on the state you live in, the crime of drunk driving might be called:

  • Driving Under the Influence (DUI)
  • Driving While Intoxicated (DWI)
  • Operating Under the Influence (OUI)

Regardless of the exact label, a DUI conviction can bring severe consequences to your life.

If you’ve been charged with a DUI, you might be wondering:

  • What are the elements of a DUI offense?
  • How do prosecutors prove DUI charges to get a conviction?
  • What are the defenses for a DUI?

If you have been charged with a DUI, it’s essential to speak with a qualified defense attorney who can “help you navigate the legal system” and ensure that you give your defense the “best shot,” says Michigan DUI defense attorney Daniel J. Larin. This article will cover the elements of a DUI offense and point to further legal resources.

Elements of a DUI Charge

Every state has its own legal definition of a DUI offense (including different labels, as we saw above). Because of this, details of the offense vary from state to state.

However, two general elements of a DUI offense hold across the board. In order to convict someone of a DUI, a state prosecutor will have to prove beyond a reasonable doubt the individual was:

  • Operating or driving a vehicle
  • While under the influence

States vary on the specifics of these elements, making it important to consult with a lawyer familiar with your state’s laws.

Let’s look at these elements in more depth.

Operating or Driving

Driving a car while drunk is the most obvious example of a DUI. But you don’t necessarily have to be driving a vehicle to be convicted of a DUI.

Some states refer to “operating” or “being in actual physical control” of a vehicle instead of “driving” a vehicle.

Operating or being in control of a vehicle includes driving but might also encompass:

  • Sitting in a parked car with the engine on
  • Being parked on the roadside or in a public area
  • Sleeping behind the wheel while intoxicated

Generally, courts will consider a few factors in determining whether someone was operating or in physical control of a vehicle while intoxicated:

  • Where was the driver? Was the person inside or outside the car? Was the person asleep behind the wheel or in the car’s back seat?
  • Where was the car? Was the individual driving the car on a public road, or was the car parked? If the car was parked, was it in a lot, on the roadside, or somewhere in the middle of the road?
  • Where were the keys? Had the driver put the keys in the ignition, or were the keys stored in the dash or kept outside the car?
  • Could the car be driven? If the car was inoperable for some reason, that detail could help the accused DUI offender’s case.

Another potential issue with the driving element is what counts as a “vehicle.”

Again, a car clearly counts, but what about golf carts, boats, snowmobiles, motorcycles, or mopeds? Many states have provisions covering these kinds of machines as well.

Under the Influence

The second element of a DUI offense is “under the influence.” Typically, this means under the influence of alcohol.

However, states target other substances as well.  “You can actually get a drunk driving charge and conviction if you’ve taken prescription medication that impairs your ability to drive–for example, a muscle relaxant or a couple of swigs of NyQuil [before getting in the car]. Your BAC wouldn’t be high at all [from taking these medications], but you could still be pulled over for [noticeably] impaired driving. With the proper evidence, [prosecutors] could convict you for something like that,” says Larin.

Depending on a state’s DUI laws, there are two general ways to prove that someone was under the influence: impairment and per se DUIs.


The first way for a prosecutor to prove impairment is to show the driver or operator was actually impaired by alcohol or another substance.

With impairment DUIs, a prosecutor doesn’t have to show a person had a specific amount of alcohol in their system. Instead, they have to show the person was intoxicated at the time of the arrest.

For example, a person might have only had a couple of beers with dinner and have a low blood alcohol content (BAC) level. Even though they’re below the legal limit, two beers were enough to impair their judgment. As a result, they drive unsafely, resulting in a pullover.

The prosecutor must prove this element beyond a reasonable doubt and can use various kinds of evidence, including:

  • Testimony about the defendant’s driving, behavior, or performance in a field sobriety test
  • Videos or photos of the incident
  • Evidence of the defendant’s intoxicated appearance or behavior
Per se DUIs

The other way a prosecutor can prove someone was under the influence is by showing they had a blood alcohol concentration (BAC) level above the legal limit of .08%. If someone has a BAC over this limit, they’re considered intoxicated by law.

A person might have multiple beers and shots and feel perfectly capable of driving a car. They might even be able to operate the vehicle fairly well. In other words, alcohol has not obviously impaired their ability to drive or operate a car. But if they are pulled over by a police officer and tested and the test shows a BAC higher than the legal limit, they are intoxicated by law.

The evidence for a driver’s blood alcohol level typically comes from administrating:

  • A breath test with a breathalyzer
  • Blood test
  • Urine test
  • Chemical test
Example: Michigan DUI Laws

 Michigan’s three-level classification of DUI offenses illustrates the differences in DUI laws:

  • High BAC. In Michigan, high BAC is .17 or higher.
  • Regular drunk living. Prosecutors prove this “either by [showing] a BAC above .08 or [that] a person’s ability has been substantially or materially impacted by their consumption of alcohol,” says Larin. Given the two ways of proving this offense, “prosecutors don’t have to prove that [a driver’s] BAC was above .08, just that due to the consumption of alcohol or controlled substances, the person’s ability was impacted that it was noticeable,” he says.
  • Impaired driving. A person’s ability was impaired even if they had a lower BAC.

DUI Penalties

Penalties for a DUI conviction vary depending on state law and circumstances. 

In most states, a first-time DUI is categorized as a misdemeanor and can bring fines and jail time. A DUI can be elevated to a felony given a few factors, including:

  • A BAC well over the legal limit of .08%
  • If someone already has multiple DUIs on their record
  • If there were aggravating factors, including property damage or harm or death to others

Misdemeanor and felony DUIs can result in several penalties. The penalties for a felony are typically similar to a misdemeanor but much more severe (longer sentences, bigger fines, etc.). Penalties include:

  • Jail time, including lengthy prison sentences for felonies
  • Fines
  • Community service
  • Increased car insurance premiums
  • Suspended or revoked driver’s license and driving privileges
  • Ignition interlock device (IID) that requires a breath alcohol test to drive a car

Learn more about the consequences of a DUI and what to do about them by reading this article.

Defenses to a DUI

Common defenses to DUI charges include:

  • Showing you weren’t intoxicated–for example, contesting the results of a BAC test
  • Showing you weren’t impaired in your operation of a vehicle
  • The officer who arrested you or tested you for alcohol failed to follow the correct procedures

The best way to formulate a defense strategy is to speak with an experienced DUI lawyer about your case.

Getting a DUI Defense Attorney

If you are facing DUI charges, it’s essential to seek legal advice from a defense attorney as soon as possible.

“When it comes to drinking and driving, people often think they can get the charges negotiated down without an attorney… What they don’t realize is that there’s often something in the case that [an attorney] would know about that becomes a defense that can lower the charge below a drinking and driving offense” entirely, says Larin.

Because attorneys have helpful expertise and experience, “it’s always imperative to at least have an attorney look at your case and see if there is something that can be done… An attorney can walk you through the system and you’ll know you’ve given your best shot” to fighting the charges, says Larin.

Fortunately, many attorneys provide free consultations, allowing the attorney to hear the facts of your case and for you to determine if the attorney meets your needs.

To see whether an attorney or law firm is a good fit, ask informed questions such as:

  • What are your attorneys’ fees?
  • What billing options do you offer?
  • What is your experience defending DUI cases?
  • What penalties could I be facing?
  • What are my best defenses and chances of success?

You can visit the Super Lawyers directory and use the search box to find a lawyer based on your legal issue or location. 

Look for a DUI criminal defense lawyer in the Super Lawyers directory.

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