The San Diego DUI Lawyer Pros 10 Effective DUI Defense Strategies

Many people believe when they’re pulled over and arrested for DUI that they have no chance of beating the charges. Fortunately, law-enforcement officials do have to follow certain laws in order to mount the correct evidence to convict you of a DUI. Did you know, there are many possible grounds of which we can use to challenge their evidence and methods? We’re going to explain to you 10 effective DUI defense options.

1) We can challenge the legality of a DUI stop outside of an established DUI check point.


Did you know? Police do not have the right to pull you over without reason. Law enforcement must have a “reasonable suspicion” that a criminal activity has occurred or is occurring. If their suspicion meets the standards, an officer has the right to briefly detain you to conduct a very limited investigation. If the officer suspects you could be driving under the influence, this may include administering some field sobriety tests or other attempts to determine if there is probable cause to make a DUI arrest.

Many DUI charges are the direct result of very common legal infractions like the ones listed below:

  • Traveling at a speed above the posted speed limit in the area
  • Weaving and driving erratically in and out of traffic lanes
  • Following the car in front of you too closely
  • Driving with the burned-out headlight or defective turn signal
  • Driving on the shoulder and using it as a road Lane
  • Failing to observe traffic lights
  • Making a wrong turn
  • Or driving very slowly or extra carefully alongside the road

Obviously, there are several legitimate reasons for law-enforcement officials to make traffic stops. But what is most important to remember that an officer must articulate a clear, reasonable cause for pulling you over in order for to be a legal stop. Law enforcement officials must also include this in the incident report when they make an arrest. If the stop that resulted in a DUI arrest was not legal, evidence collected during the process of the DUI investigation is not going to be admissible in court. With all evidence being deemed invalid and thrown out of the court, the state will be not be able to make an effective case against you and the charges are likely to be dismissed by the DUI court.

2) Disputing suspicion you were under the influence.

What a law-enforcement official pulls you over. The officer will be very aware of your appearance and your behavior while he or she is examining and questioning you. The officer might note they smell drugs or alcohol, observe red bloodshot eyes, and maybe slurred speech or poor motor functioning. These are all observations that an officer is likely to make note of in a report after your DUI arrest. Whatever these stated traits and other traits they may deem as intoxicated or not necessarily related to drinking alcohol or ingesting drugs. Additional medical conditions can cause these factors that may lead them to believe you are under the influence of drugs and/or alcohol and they include:

  • A specific medical condition
  • Side effects of some sort of medication that you’ve been prescribed for example, cold medicine
  • Over the counter personal products like mouthwash

All three of these could be considered to possibly show up as intoxication symptoms and related to alcohol ingestion or drug intoxication. There is also a chance that we could dispute that any of the signs were present at all and discredited the officers arrest account. Footage from dashboard cameras may not match up with what’s in a written report. A video from the police holding area may also show that you are not acting intoxicated and could contradict testimony from the officer’s observations.

3) Questioning the efficiency of field sobriety test.

Law-enforcement officers have for years commonly used the field sobriety test as a way to identify people who could be intoxicated or under the influence of drugs. The problem with this is that the specific assessments have been shown to be poor indicators for alcohol or drug intoxication.

Primarily field sobriety test assess a persons ability to recite the alphabet backwards or touch one’s nose and have shown to be incredibly unreliable in establishing one’s level of intoxication. Some of these test are considered to be extremely unreliable such as the one leg stand, the walking turn around and horizontal gaze nystagmus assessment are all tests that have been demonstrated to be extremely flawed in many cases.

Below are some potential factors that could lead someone to perform poorly in the field surprised he tested ministered by an officer:

  • Having a physical ailment or being overweight
  • Poor footing or poor weather conditions
  • Unstable footwear and or restrictive clothing
  • Poor coordination

The reality is there are several additional factors that could hinder a person’s performance in a field sobriety test. Considering that most of these assessments are very unreliable as indicators of intoxication, it’s very possible to discredit the evidence collected by the officer during their administration of these field sobriety tests. There is no guarantee that if we are to discredit the filed sobriety tests your case will be dismissed, but it can help to reduce the overall amount of evidence collected against you and cause issues of credibility for the prosecution.

4) Challenging blood alcohol concentration results from the use of a breathalyzer.

Just as field sobriety tests can be flawed so can blood alcohol concentration results from a breathalyzer. Bear in mind, a breathalyzer is a machine that needs to be calibrated properly in order to give an accurate reading. The slightest error in calibration could mean the difference between a .06 and a .08 or .09 blood alcohol concentration reading. If this is you, that difference could mean a DUI arrest and a conviction. There are many potential reasons that a breathalyzer device may not provide an accurate blood alcohol concentration reading and some of these include:

  • Improper maintenance- All breathalyzer equipment must be properly maintained and calibrated in order to deliver an accurate result. Without proper, and regular maintenance, the device could show that a person has an inflated blood alcohol concentration level that is not accurate.
  • Equipment malfunction- Even if the best equipment is calibrated properly there is a potential for the equipment to fail. Many studies have shown that devices can fluctuate giving inaccurate readings.
  • User error– Again a breathalyzer is a piece of equipment that must be used properly. Unfortunately the user could be inexperienced and or careless and not take a proper blood alcohol concentration rating.
  • Health conditions- Sometimes breath tests are wrong when devices can mistake naturally occurring bodily substances with ingested alcohol. Certain bodily traits and people with certain health conditions could be negatively affected by such errors.
  • Use of over-the-counter products.– The use of mouthwash and other oral hygiene products can result in a heightened blood alcohol concentration readings. Unfortunately breathalyzer devices cannot make the distinction between alcohol and mouthwash.

These are some of the more common DUI defense strategies that we can use to undermine blood alcohol calculator results. There are others and we could effectively call into question any breath test by an expert witness who are much more familiar with how devices operate and their potential for giving inaccurate readings.

5) Challenging results of blood test.

Blood tests are also used to assess a persons blood alcohol concentration levels and are most likely performed after a person has been arrested for driving under the influence of alcohol or an illicit substance. Each test is typically conducted at a medical facility in a particular area located in the police station. They can also be conducted inside specialize law enforcement vehicles that are kept at DUI checkpoints.

While blood tests are regarded as the most reliable form of blood alcohol concentration testing available today to law-enforcement officials. Even when a sample of blood is taken from an alleged drunk driving offender and tested inside a laboratory there is a possibility for errors occurring from this test due to false positives.

Potential issues that could cause a false positive include:

  • Inexperienced or unqualified laboratory analysis– Each state has its own laws regarding people who do this work and they must obtain proper training and licensure. If they fail to renew any specific licensure or do not attend any required courses they can open the door for us to contest your blood alcohol concentration reading.
  • Outdated or poorly maintained equipment- Anytime you’re taking and analyzing blood it’s obviously a precise procedure. Even if the person using equipment is qualified there could be old or poorly kept equipment that could result in an inaccuracy. This could cause an erroneous blood alcohol concentration reading.
  • Chain of custody issue- From the time the blood is drawn from your body it is very important that this blood be handled within proper protocols. It must be stored and transferred according to establish protocols. Expert witnesses we have access to or able to often times show that a breakdown of chain of custody protocols has occurred during the testing process of your blood sample.

If we are able to successfully challenge the blood test your case would almost surely be a dismissal. Taking into consideration the blood alcohol concentration results from a blood test is the strongest evidence that a prosecutor can present to the court makes it almost a sure dismissal if this evidence is discredited

6) Proving that a DUI checkpoint arrest was illegal.


DUI checkpoints are extremely controversial all throughout the 50 states. Many cases questioning the constitutionality of DUI checkpoints have made their way throughout the court systems over the years with courts trying to determine if the checkpoints are an infringement of the fourth amendment rights of American citizens. Only 30 states in the United States actually utilize DUI checkpoints.

The Supreme Court has upheld the legality of DUI checkpoints however the circumstances of which law-enforcement roadblocks are set up have to follow certain protocols. If these protocols or not followed closely a traffic stop could be deemed illegal. Following requirements must be made regarding DUI checkpoint

  • Every driver must be stopped for a DUI inspection. Law enforcement officials do not have the discretion to stop every other car or stop cars randomly.
  • The safety of all drivers must be taken into account, this would include appropriate lighting and adequate notice of the road block ahead.
  • Constitutional privacy rights must be observed by the law-enforcement officials during the entire stop.

If any of the above provisions are violated during a stop at a DUI checkpoint you may have a good argument as to the legality of your stop. If this is the found to be the case your DUI charge would typically be dismissed considering the evidence collected against you would become inadmissible in court.

7) A law enforcement officers failure to mirandize.

In America it is law-enforcement’s job to inform every American of their rights. When taken into custody it is the job of the officer to inform you that you’re not required to make incriminating statements against yourself. What you say can and will be used against you in a court of law. And most importantly they need to inform you that you have a right to an attorney.

If they do not follow the Miranda rights properly under the law. All evidence collected in the course of your DUI arrest may be ruled inadmissible in court. If this were to occur the prosecution would have no evidence and you would most likely receive a dismissal of charges.

8) Failure for arresting officer to issue an implied consent warning.

The implied consent warning means that if a law-enforcement official believes that you are intoxicated he or she must request that you take a blood alcohol breathalyzer test. If they demand that you take this test without asking you it would be a violation of the implied consent laws.

If the law-enforcement official has not issued you the implied consent warning during the course of your DUI arrest any evidence that is collected after that point could be ruled inadmissible in a court of law. Again a chemical blood alcohol concentration test is considered to be the most reliable form of evidence for prosecutors to use against you in court. If this evidence is deemed inadmissible you would most likely receive a dismissal of charges.

9) Falling victim to racial profiling or other police misconduct.

As you may know, it is illegal for law-enforcement officials to single out minorities for traffic stops or arrest. Unfortunately, in today’s society it is well documented that law-enforcement officials do racially profile.

If you believe you were arrested or pulled over on suspicion of DUI based on your race you may have an opportunity to avoid punishment under the laws associated with driving under the influence of alcohol or another illicit substance. If we can demonstrate in a court of law that your stop was race-based it would open up the possibility to question the police officers motives.

10) Making the “rising blood alcohol content” argument.

Because alcohol is primarily absorbed through your small intestine it takes time for the bloodstream to absorb the alcohol throughout your body. Very few people understand how long it takes for alcohol to actually be absorbed into the body and cause impairment. Research leads us to believe that your body does not achieve peak intoxication until 30 to 90 minutes after an alcohol drink is consumed.

If you were to be pulled over and arrested for a DUI I between 30 and 90 minutes after your last alcohol drink was consumed you could make the argument that your blood alcohol Concentration was lower than .08.when you were driving. Bear in mind if your breathalyzer test is done 45 minutes after your pulled over and your blood alcohol concentration is over .16 you would probably not have an argument. However, if you were pulled over and your breathalyzer was conducted 60 minutes after your first drink and your blood alcohol concentration was .08 there’s a high likelihood you would not be legally drunk.

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