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Breath Testing in Grand Rapids DUI Cases

Michigan law makes it a crime for drivers over the age of 21 to operate a motor vehicle with a blood alcohol content (BAC) of 0.08% or higher. Due to Zero Tolerance laws, the legal limit for minors is much lower. If you take a Michigan breath test and the results show you are over the legal limit, you may be arrested and charged with driving under the influence (DUI) in Grand Rapids.

Types of Breath Tests

Three types of tests may be administered in order to determine your BAC—breath, blood, and urine. Of the three, breath testing is the most commonly utilized by law enforcement agencies. Breath tests are often referred to as breathalyzer tests, which is the brand name for a specific breath-testing machine.

In a drunk-driving case, you may be asked to take two different types of Michigan breath tests. One is a portable, roadside test and the other is a more accurate test administered at the detention center. The portable test is used to determine if there is probable cause to arrest you for driving under the influence. In most cases, the numerical value from this test result cannot be used in court, because the results are not always accurate. However, if the “rising blood alcohol” defense is used during a case, the prosecutor may file a motion to have the test results admitted into evidence to show your BAC at the time you were driving.

The second test is administered at the jail or police station—the results from this test are considered the most scientifically accurate and can be used as evidence against you. Michigan law enforcement agencies use “DataMaster” breath-testing machines, a table-top machine that prints out the results after you have taken the breath test.

Administrating a Test

Michigan administrative rules require the police to take two breath samples; however, the courts have ruled that only one sample is really required. If two breath samples are taken, the results must be within an allowable range of error or they may be thrown out. The range of error accepted depends on the specific results of the test.

In order to prove the quality of the test results, Michigan’s administrative rules also state that the prosecution must prove that the breath-testing machine was in working order and properly maintained at the time of your test.

The way you blow into DataMaster can affect your breath test results. If you blow into the unit too hard, a pressure malfunction may cause a false reading. Hyperventilating or leaning forward while seated can also cause inflated test results.