Anyone who is charged with driving under the influence in Southern California will need a good DUI defense lawyer who evaluates every piece of evidence, interrogates witnesses and experts, and challenges DUI test results on a client’s behalf. With so much at risk – huge fines, the loss of the driving privilege, and potential jail time – it is imperative for a DUI suspect to hire an attorney with extensive knowledge of California DUI law and considerable experience handling driving under the influence cases.


A motorist charged with driving under the influence in California has several options if he or she chooses to mount a defense. “Affirmative” defenses to DUI – defenses that admit the evidence fully supports the charge but insist that the defendant should nevertheless be found not guilty. These are used in some rare cases, but it is more common to fight a driving under the influence charge by challenging the arresting officer’s observations or by challenging the integrity of the evidence.

Prosecutors in driving under the influence cases tend to focus on a suspect’s driving pattern.  Arresting officers routinely testify that suspects were driving in a manner “consistent with” someone driving under the influence of alcohol or drugs. An experienced DUI attorney challenges “driving pattern” testimony and evidence by asking the officer to explain the ways a suspect was driving properly and safely. A good DUI attorney will also lead an arresting officer to admit that the majority of traffic violations are committed by drivers who are sober and that someone’s driving “pattern” is not a reliable indicator of driving under the influence.

In Southern California, DUI defendants should consult with an experienced Orange County DUI defense attorney to determine which line of defense may be most appropriate in any particular case. Listed here are brief introductions to the affirmative defenses, common defenses, and other defenses that California DUI attorneys have used successfully in the past when advocating in the defense of their clients.



  1. The Duress Defense: This is the defense that the defendant had to drive to avoid a serious injury or death. For example, someone forces an intoxicated person to drive at gunpoint, or an intoxicated person is fleeing and believing that his or her safety is in danger.
  2. The Entrapment Defense: When an officer asks someone to drive while intoxicated, and the officer then arrests that person for doing so, it’s entrapment. The defendant must also prove that he or she would not have been driving under the influence if not for the alleged entrapment.
  3. The Mistake of Fact Defense: This is the DUI defense that can be offered if a suspect honestly believed that he or she was not intoxicated while driving. It might be offered, for example, if someone believed that the intoxicating effect of a prescription medication had faded enough to make driving safe.
  4. The Necessity Defense: This is the argument that the defendant “had” to drive to prevent a greater evil. The defense must prove that the driver had no other realistic alternative and that the “greater evil” avoided was worse than the potential for harm caused by driving under the influence.
  5. The Involuntary Intoxication Defense: This defense can be presented if a suspect consumed alcohol without knowing it. For example, if someone slipped alcohol into a suspect’s food or drink without the suspect’s awareness, the involuntary intoxication defense might be appropriate.


  1. The Improper Stop Defense: This is perhaps the most common defense offered by DUI attorneys. It is the claim that the police officer did not have sufficient, legal probable cause to make the traffic stop in the first place.
  2. The Rising Blood Alcohol Concentration Defense: This is a claim by the defense that the suspect’s blood alcohol content level was below the legal limit while the defendant was driving but actually increased after the traffic stop and before the breath test. This is possible because recently consumed alcohol takes a few minutes to absorb fully into the system.
  3. The Field Sobriety Test Challenge: If a field sobriety test was improperly conducted, a DUI defense lawyer will challenge it. The horizontal gaze nystagmus (HGN) test, which is supposed to detect the eye movements associated with intoxication, is a frequent target of DUI defense attorneys.3
  4. The Breathalyzer Test Challenge: A DUI attorney may challenge the breathalyzer test conducted at the scene of the arrest and/or the test conducted later at a hospital or police station. Was the officer properly trained, the test properly conducted, and the testing device properly calibrated and maintained? Alcohol traces from food particles or acid reflux can make a breath test inaccurate, and conditions such as GERD, heartburn, diabetes, hypoglycemia, or an Atkins-style diet can also make a breath test inaccurate.
  5. The Blood Test “Chain of Custody” Challenge: This defense strategy questions the administration of a blood test and/or whether it was tampered with or otherwise mishandled at any point in the process.


  1. The Accused was not the Driver: Questions may emerge in some DUI cases regarding whether the person charged with driving under the influence was actually the driver of the vehicle. Especially when an officer arrives at an accident scene and has not actually observed anyone driving, the question regarding who was actually behind the wheel can be tough to answer with certainty.
  2. The Police Acted Improperly: When this defense is offered, there must be evidence and/or testimony that a police officer violated the defendant’s civil rights, fabricated a DUI report, or otherwise acted improperly. This defense is also appropriate when an arrest is made at a DUI checkpoint that has been illegally or improperly conducted.


Anyone arrested and charged with driving under the influence in Southern California should speak with an experienced Orange County DUI attorney. A good DUI lawyer may offer one of the defenses discussed above or may instead pursue another defense strategy. Of course, the very best way to avoid a DUI conviction is to avoid a DUI charge, and the best way to avoid a DUI charge is the simple advice you’ve heard many times – don’t drink and drive.