Wisconsin OWI Evidence: WI DUI Chemical Test Evidence

Following an arrest for an OWI in Wisconsin, a suspect is typically taken to a police station for chemical testing. Wisconsin DUI law permits the police to request a sample of your breath, blood, or urine for the presence of alcohol and/or controlled substances. The police have the discretion of which test(s) they will administer. Wisconsin law does not limit the amount of chemical tests that the police may request. A refusal to submit to a chemical test upon a lawful request will result in the suspension of the person's driver's license. A Wisconsin OWI suspect's test results or their refusal is admissible against them in court. In certain circumstances, the police may forcibly draw blood without first obtaining a person's consent. For more information on refusals and the administrative license suspension process, click on the Wisconsin Driving tab.

PRELIMINARY BREATH TESTS (PBTs) - PBTs are handheld breath testing devices that are used on scene prior to an OWI suspect's arrest. The results of the PBT are not admissible in court. Instead, the purpose of the PBT is to help aide the officer in his determination of whether to make an arrest. There is no penalty for refusing to submit to a PBT.

EVIDENTIARY BREATH TESTS - Evidentiary breath testing is conducted down at the police station after a suspect has been placed under arrest. The state of Wisconsin uses a breath machine called the Intoximeter EC/IR. The Intoximeter is a breath testing machine that measures the amount of alcohol present on a person's breath. A person arrested for OWI will be required to give 2 valid samples of their breath upon request. Failure to provide 2 samples will be considered a refusal. The results of an evidentiary breath test are admissible in court. All breath testing must comply with the rules promulgated by the Department of Transportation. Failure to follow procedures may affect the validity and admissibility of the test result.

BLOOD TESTS - Wisconsin law allows police officers to request a sample of an WI OWI suspect's blood in order to test for the presence of alcohol and/or controlled substances. Blood tests are more reliable than breath tests, but they are also more invasive. Unlike breath tests that can only detect the presence of alcohol, a blood test may also detect levels of drugs and/or controlled substances. All blood testing must be conducted in accordance with the rules and regulations governing the administration of chemical test. Failure to properly test, preserve, analyze, or label the sample will affect the validity and admissibility of the test result.

URINE TESTS - Urine testing is more commonly conducted in OWI cases where drug impairment is suspected. Whether a suspect will be requested to provide a urine sample is in the discretion of the officer conducting the arrest.

RIGHT TO AN INDEPENDENT TEST -  Wisconsin DUI law provides OWI suspects with the right to have an independent and/or additional chemical test at your own expense. The arresting officer must communicate this right to you and make reasonable efforts to accommodate you once your request for such a test has been made.