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DUI Evidence Gathering: Can Police Force a Driver to Do a Blood Test?

Posted on in DUI Defense

IL DUI lawyerWhen a police officer suspects a driver of DUI, the officer has to gather sufficient evidence to support that suspicion. If the officer does not build a strong enough case, the driver cannot be charged with and eventually convicted of DUI.

What kind of evidence are we talking about? There are four kinds of evidence that can be used to support a DUI conviction. Specific rules apply to each type of evidence, including whether or not a driver can refuse to participate and what happens if the driver refuses.

1. Law Enforcement Observations

The officer will make observations of the driver and the car. The officer might witness erratic driving behavior such as weaving across lanes, see alcohol containers or drug paraphernalia in plain sight in the car, smell alcohol or marijuana on the driver, and so on. The driver can do nothing to prevent the officer from gathering this type of evidence.

2. Field Sobriety Tests

The officer will ask the driver to perform standardized field sobriety tests at roadside. Failure on all three tests is considered to be strong evidence of DUI if the tests are properly conducted by the officer. Remember, DUI is about driver impairment, not just a specific blood alcohol concentration (BAC). A driver with a BAC of just .05 (below the legal limit of .08) can be convicted of DUI if there is other evidence of impairment such as failure on field sobriety tests and police observations. A driver is free to refuse field sobriety tests with no legal penalty, thus denying the police this type of evidence.

3. Portable Breathalyzer Tests

The officer will ask the driver to submit to a portable breathalyzer test at roadside. (This of course only works for alcohol-based DUI. There is currently no widely-accepted roadside test for marijuana and other drugs.) A PBT result over the legal limit is generally considered sufficient evidence for an arrest but is not accurate enough to be admissible in court. A driver is free to decline the PBT with no legal penalty.

4. Evidentiary Testing

At this point, if the officer believes there is reasonable cause to arrest the driver for DUI, he can do so. However, if the driver has declined the roadside tests, the officer has to be sure he has enough observational evidence to back up his decision.

The driver will then be taken to a police station or hospital for evidentiary testing of breath, blood, or another bodily substance. Evidentiary testing is conducted by methods considered accurate enough to be admissible in court.

A driver can decline evidentiary testing, but there is a legal penalty in the form of a longer statutory summary suspension of driving privileges. Under Illinois law, a driver who submits and fails testing (e.g., BAC of .08 or higher) will lose his license for 6 months on the first offense and 12 months on any subsequent offense. But a driver who refuses evidentiary testing will automatically have his driver’s license suspended for 12 months on the first offense and three years on any subsequent offense, no matter what his BAC actually is.

Can Police Force a Driver to Submit to a Blood Test?

If a driver will not voluntarily submit to an evidentiary breathalyzer or other test, the police must obtain a search warrant allowing them to take a blood sample from the driver for drug/alcohol testing. In the past, this might have taken several hours, allowing time for drugs and alcohol to leave the bloodstream. But many police departments in Illinois have now set up expedited procedures enabling them to get warrants very quickly. Police in a number of counties can generate an “e-warrant” right in a squad car and send it to a judge for near-immediate electronic approval.

DUI Defense Attorney in Oak Brook

If you have been charged with driving under the influence in the Oak Brook area, you need to consult an experienced DuPage County DUI defense lawyer as soon as possible. The attorneys at McMahon Law Office will diligently examine the police evidence against you and gather additional evidence as well in order to build the strongest possible defense for you. For a free consultation, call 630-953-4400.








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