Driving Under the Influence (DUI) case's strongest evidence are usually the results of a chemical test, including a breath test, blood test, or urine test showing that the driver was intoxicated with alcohol, prescription drugs, or a controlled substance.
The prosecutor will argue that this refusal demonstrates a "guilty conscience", i.e. the driver's belief that if he submitted to the chemical test, the test results would show that he was intoxicated from alcohol or impaired by prescription drugs or other controlled substances. The prosecutor will then attempt to admit evidence that the driver "refused" to submit to the test and other circumstantial evidence.
In determining whether to admit or exclude the evidence that the driver refused to submit to the test the Court will consider state and federal constitutional provisions, the rules of evidence, common law provisions, statutory rules, and administrative rules. Furthermore, if the law enforcement officer violates a driver's constitutional or statutory rights to an attorney before the blood, breath or urine test, then the Court can exclude or throw out any evidence that the defendant declined to take the chemical test.