You pull over as soon as you hear the sirens or notice the flashing lights behind you. When the officer walks up to your vehicle, you readily admit that you had been at a party or out to dinner because you only had one drink. The officer has you exit the vehicle and eventually, you perform a chemical breath test.
You assume that the breath test will exonerate you and end the interaction. However, the officer informs you that you failed the test. You probably feel confused and frightened when the officer proceeds to arrest you.
Although you do eventually secure your release, it is only after a judge arraigns you for driving under the influence (DUI). You know you only had one drink and were definitely not drunk when the officer pulled you over. Do you have any choice but to plead guilty since there is a failed breath test that contradicts your version of events?
Chemical breath tests make mistakes more often than people realize
Chemical testing and physical evidence seem like the best way to prove allegations of criminal offenses. They aren’t easy to manipulate or subject to major mental errors, like human witnesses. They are far less open to interpretation than certain kinds of forensic evidence.
In the case of chemical breath tests, the devices used by police officers rely on straightforward and easy-to-understand science. Judges and juries have long accepted the readings produced by such devices as very strong proof that a driver had inappropriate levels of alcohol in their body. However, that has begun to change.
More and more research supports the claims that chemical breath tests aren’t that reliable. They can return false positive test results if people have certain medical conditions or take certain medications. Officers can make mistakes when they administer the tests, and police departments can fail to do the necessary maintenance and calibration to ensure accurate test results.