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DUI Proving Impairment or Intoxication

DUI is the term that we commonly use to refer to all operating while intoxicated, impaired or drunk driving cases. It is just a simple way to write or talk about this complex topic.

It is not well known to the general public but there are 2 distinct classes of DUI cases in Michigan:

  • DUI's that DO NOT REQUIRE proof of intoxication or impairment
  • DUI's that REQUIRE proof of intoxication or impairment
DUI-OWI Cases: Proof of Intoxication or Impairment Not Required

In Michigan, you can be convicted of a drinking or drugged driving offense, regardless of your intoxication or impairment under certain specific circumstances. These are called "per se" cases that do not require any proof of intoxication or impairment. There are "per se" DUI cases for alcohol and also for drugs. The breath, blood or urine test results are the key to "per se" cases. The following offenses are classified as "per se" where intoxication or impairment is presumed:

  • OWI w/High BAC of .17 or more (Super DUI)
  • OWI: Operating while intoxicated, BAC .08 to .16
  • Zero tolerance, under age 21, BAC .02 but less than .08
  • OWPD, any presence of Schedule 1 drugs, cocaine or marijuana (w/o a medical marijuana card)

ALCOHOL "per se" cases: Michigan has a legal blood alcohol content (BAC) cutoff of .08 to .16 for OWI and .17 or more for OWI with a High BAC which do not require proof of impairment or intoxication.

DRUG "per se" cases: Drug "per se" cases are based upon a positive test result with any presence of a Schedule 1 drug such as heroin, cocaine or marijuana.

Police and prosecutors prefer the DUI cases that do not require any proof of intoxication which is no surprise.

Attorneys are never on board with laws that make someone strictly liable or automatically guilty of a crime. All aspects of a DUI must be proven beyond a reasonable doubt: including the validity of the traffic stop and proof that the accused party operated the vehicle. ABDO LAW also knows that chemical test results are not perfect. There may be grounds to fight a "per se" case if the levels do not represent recent drug use or testing procedures were not strictly followed by the police.

DUI Cases: Proof of Intoxication or Impairment is Required

A person may be charged with a DUI in any situation where the police believe that the person operated a vehicle while impaired or intoxicated. However, intoxication or impairment must be proven by admissible evidence unless the test result establishes a "per se" violation. In the following scenarios, driving under the influence or impaired must be proven.

  • BAC below legal limit of .08: In Michigan, a BAC breath or blood test result below .08 does not create any presumption of intoxication. However, a person that has a test result below the legal limit of .08 can still be charged with OWI or OWVI if intoxication or impairment is shown. The test result (below .08), in and of itself, is not proof of intoxication or impairment. Additional evidence would be required at trial to prove intoxication or impairment.
  • Prescription Medications: It is legal to drive after using prescription medications. Medications for pain, sleep and psychological disorders are widely used by millions of people without any side effects. However, a person may be charged with an OWI or OWVI if the officer believes that the medications caused intoxication or impairment. A positive test result for prescribed medications alone does not prove intoxication or impairment. Proof of intoxication or impairment is required. However, test results that show extremely high levels of prescriptions, or the combination of other medications and alcohol, can be damaging evidence in a DUI prosecution.
  • Medical Marijuana: In Michigan, it is illegal for a person to operate a motor vehicle with any presence of marijuana without a current medical marijuana card. However, a medical marijuana card is not a defense to a DUI if the person is impaired or under the influence of marijuana.

The above scenarios differ from "per se" DUI cases because there is no automatic presumption of impairment or intoxication. Although the test result is admissible in evidence, additional proof or evidence is required to prove intoxication or impairment as we explain below; Methods Used to Prove Intoxication or Impairment.

Methods Used to Prove Intoxication & Impairment

The chemical test result along with other testimony by police and civilian witnesses may be used at trial to establish a DUI. Keep in mind that every one of these methods can be challenged by a DUI defense lawyer.

  • Observations: Police and civilian witnesses may testify as to the driver's objective signs of intoxication which include: a distinct odor of alcohol coming from the driver, red, watery eyes, unsteadiness and slurred speech.
  • Field Sobriety Tests: Police will assess a driver's ability to perform field sobriety which are designed to test a driver's balance and motor skills. Police may ask a driver to perform tasks such as walking heel-to-toe in a straight line, standing on one leg, or reciting the alphabet backwards. If a driver fails one or more of these tasks, the officer may request that the driver take a chemical test to measure for drugs or the driver's blood alcohol content (BAC). Everyone has their own individual mannerisms, body movements and ways of speaking. A sober person may appear to be impaired because certain behavior or speech does not fit neatly into a police officer's expectations.
  • Chemical Tests: Breath, blood or urine tests showing the presence and levels of alcohol or drugs may be admitted into evidence. A driver's blood alcohol content BAC provides a measure of the percentage of alcohol in the blood. A breathalyzer, used for testing blood/alcohol level, provides an immediate response and printout of the test results. Drug test results are submitted to the Michigan State Police for forensic testing. Drug test results can take several months before they are returned and a case is entered in the court system.
  • Driving Ability, Accident: The driving ability, or evidence of an accident, is admissible to show impairment or intoxication in DUI prosecutions. Being at fault in an accident, erratic driving, weaving, driving against traffic on a one-way road, driving on the shoulder, driving too slow or too fast, or any number of reasons may indicate that someone is under the influence.
Challenging Breath, Blood, Urine Tests for Alcohol or Drugs

The chemical test results for alcohol or drugs are subject to admissibility in DUI court proceedings pursuant to the Michigan Rules of Evidence. Chemical test levels, testing procedures and protocols may be contested before or during trial. The accused party is also entitled to obtain a clean sample of the breath, blood or urine collected at the time of a DUI incident for independent testing. The use of expert witnesses may also be utilized when technical aspects of testing process, test results or testing equipment are disputed in DUI cases.

The Prosecutor Does Not Have the Final Word

Every testing method has flaws that can be challenged in a courtroom.

The judgment of police officers and others, an automobile accident or erratic driving does not always equal impairment. You are entitled to aggressive representation and our Metro Detroit DUI defense lawyers can explain how every aspect of a DUI case is subject to a counter-attack.

Macomb, Oakland, Wayne, & St. Clair

EMAIL or CALL Abdo Law for a FREE CONSULTATION. Phone messages after business hours are forwarded to our attorneys. We offer same day, evening, weekend appointments and the ability to retain us over the internet. Payment plans and all credit cards accepted.

CALL: Metro Detroit: 586-412-5555 or Toll Free: 844-Got-Abdo

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