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The facts and circumstances of each DWI arrest are different. Consequently, the defenses that may apply to your case can only be determined by meeting with you and discussing the facts and circumstances of your case in detail. DWI cases are complex and, as a result, numerous possible defenses may exist depending on the facts of the case. Most defenses fall into one of the following categories:
Intoxication is not enough to prove a DWI. The prosecution must also prove that the defendant was operating a motor vehicle. This may be difficult if, as in the case of accidents, there are no witnesses to testify regarding who was driving the vehicle.
- Probable cause.
Evidence in a criminal case will be suppressed if the officer did not have legal cause to (a) stop, (b) detain, and (c) arrest. Sobriety roadblocks present particularly complex issues
- Miranda Warnings.
Incriminating statements may be suppressed if Miranda warnings were not given at the appropriate time. The minimum Miranda Warning required by the U.S. Supreme Court is:
You have the right to remain silent. Anything you say can and will be used against you in a court of law. You have the right to speak to an attorney, and to have an attorney present during any questioning. If you cannot afford a lawyer, one will be provided for you at government expense.
- Implied consent warnings.
If the officer did not advise you of the consequences of refusing to take a chemical test, or gave you incorrect or confusing information regarding the consequences of refusal, this may impact admissibility of the refusal -- as well as the license suspension imposed by the motor vehicle department.
- "Under the influence".
The officer's observations and opinions as to intoxication can be questioned. For example, the circumstances under which the field sobriety tests were given and the subjective nature of what the officer's opinion that you were intoxicated may be questioned. Also, witnesses can testify that you appeared to be sober.
- Blood-alcohol concentration.
There exists a wide range of potential problems with blood, breath or urine testing. For example, most breath machines will register many chemical compounds found on the human breath as alcohol. And breath machines assume a 2100-to-1 ratio in converting alcohol in the breath into alcohol in the blood when in fact this ratio can vary widely from person to person (and within a person from one moment to another). Radio frequency interference can also result in inaccurate readings. These and other defects in analysis can be brought out in cross-examination of the state's expert witness, and/or the defense can hire its own forensic chemist.
- Testing during the absorptive phase.
The blood, breath or urine test will be unreliable if done while you are still actively absorbing alcohol (it takes 30 minutes to three hours to complete absorption; this can be delayed if food is present in the stomach). Thus, drinking "one for the road" can cause inaccurate test results.
- Retrograde extrapolation.
This refers to the requirement that the BAC be "related back" in time from the test to the driving. Again, a number of complex physiological problems are involved here.
- Regulation of blood-alcohol testing.
The prosecution must prove that the blood, breath or urine test complied with state requirements as to calibration, maintenance, etc.
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