A driver can be charged with either a DUI (driving under the influence) or DWI ( driving while intoxicated). In a DUI case, the prosecution must prove the person being charged, drove the vehicle and was “under the influence.” This means the person consumed prohibited amounts of alcohol. Most DUI cases depend on the state law. 

What Are the Affirmative Defenses to DUI?

There are several affirmative defenses to a DUI charge are those include:

  • Necessity is allowed when the driver needs to operate the vehicle to prevent a greater evil. The person must prove that the greater evil was more serious than the harm caused by the DUI; 
  • Duress is when someone forces the person to operate the car while they are intoxicated by force or threat of force; 
  • Entrapment is when an officer encourages the driver to become intoxicated; 
  • Mistake of fact is when the person genuinely believed that they were not intoxicated and;  
  • Involuntary intoxication is when someone consumed alcohol without the knowledge of it. 

What Are the Common Defenses Used for a DUI Charge?

Although there are affirmative defenses available for the driver charged with DUI, there are also other common defenses used in those circumstances:

  • Improper stop: Lawyers will often argue that their client initial stop lacked probable cause by the officer and therefore was invalid; 
  • Accuracy of the field sobriety test (FST): A test must be conducted and administered accurately. The horizontal gaze nystagmus (HGN) test is often challenged, this test detects eye movements in regards to intoxication;  
  • Accuracy of the portable breathalyzer test: The lawyers can challenge the test if there were intervening factors involved such as indigestion and vomiting, and whether the test was properly conducted;  
  • Accuracy of the standard breathalyzer test: This is conducted mostly after the arrest at the police station; 
  • Chain of custody of the blood test: This is a consideration of whether the test was tampered with and; 
  • Rising blood alcohol concentration: This has to do with recent consumption of alcohol and it not reaching the prohibited alcohol level.

Besides these, there are also some non common defenses used against DUI charges:

  • The accused was not the driver and; 
  • Improper police action.

Some states do not require that the car be in actual motion to be charged with a DUI. As long as the person had physical control and was operating the car, it is enough to charge. Therefore, you can still be charged for a DUI if you were in the car.

What Are the Defenses for Arrest Procedures in a DUI?

Police officers need probable cause to stop the vehicle for a DUI. Therefore, if there is no valid reason for the police to conduct the traffic stop, the evidence following the arrest can be deemed inadmissible. Furthermore, besides having a valid traffic stop, the officer must also have a reason to believe that the driver broke the DUI laws.

This usually occurs after the police observations and after the various tests for sobriety are administered. If the tests prove that your alcohol blood level was above the prohibited amount this is enough for the judge to find probable cause. Additionally, there must be a recitation of the Miranda rights if the person is in police custody and given before any questioning begins. 

How Do I Challenge the Officer’s Testimony?

Generally most states have two types of DUI charges. First, there is an “impairment” DUI and second there is a “per se” DUI. For the impairment here are the list of observations an officer can cite

  • Poor FST performance; 
  • The odor of alcohol; 
  • Bad driving; 
  • Bazaar behavior; 
  • Slurred speech and; 
  • Bloodshot eyes.

For defense purposes, it may be challenging to counter the officer’s observations. However, each circumstance is different. For example, you can introduce another witness who has a separate encounter of the event of the time you were arrested for the DUI. But often times the prosecution rules out that witness claiming they are biased if they were the passenger in the car with the driver. You can also provide valid explanations for your appearance and behavior.

Additionally, if the officer fails to warn you about the necessary information, it could affect the admissibility of the tests. For example, if you refuse to take a chemical test,your license can be suspended and if the officer failed to inform you about this, the test results may not be admissible in court.

When Do I Need to Contact a Lawyer for Help with a DUI Case?

If you were arrested or charged with a DUI there may be options available for you to receive a lesser punishment based on your circumstances. However, each state varies on this and it depends on your situation.

If you believe that your rights as a driver have been violated or there was some misconduct from the police officers, you may have a defense in your DUI charge. Therefore, to consider the DUI defenses, it may be useful to seek out a DUI lawyer who can assist in resolving those issues for you.