Presumption of Innocence in DUI Cases

The presumption of innocence is the founding premise of the American criminal justice system. It states that you are presumed to be innocent of a crime unless and until you are found guilty in a court of law. In DUI cases, the presumption of innocence is important because drivers have many available defenses to DUI charges that may not be obvious at first, such as failure to follow proper breath test procedures. If drivers were presumed guilty of a DUI without the chance to establish defenses, their cases might turn out very differently.

The case of Morissette v. United States, 342 U.S. 246 (1952), established that conclusive presumptions go against the presumption of innocence and may not be part of the law. Presumptions can be phrased as “if…, then” statements, such as “If the defendant blew a .08 on the breathalyzer, then he is guilty of a DUI” or “if BAC is taken within three hours of driving, then it will be the same level as when driving”. A conclusive presumption would have legally binding effect once established, with no opportunity to provide evidence that the presumption is incorrect.

In Morissette, the defendant took some old bomb casings from an Air Force range. He was charged with knowingly converting government property, and the defendant asserted that he took the casings because he thought that they were abandoned. At trial the judge’s instruction to the jury implied that the defendant’s intent to steal was legally presumed because he admitted to removing the casings from the range intentionally. However, a conviction actually required that the defendant know the cases were not abandoned – and the defendant thought they were abandoned. The Supreme Court reversed the defendant’s conviction because his knowing intent in taking the casings was an essential element of the crime, and a conclusive presumption that he had that intent just because he took the casings violated the presumption of innocence.

Essentially, this crucial Supreme Court ruling established that presumptions are always rebuttable, not conclusive. Rebuttable means that while one side in the case can establish the presumption, the other side has the opportunity to counter it with evidence to the contrary. For example, the defendant in Morissette presented testimony that he believed the casings were abandoned to rebut the presumption that because he took them, he intended to knowingly convert government property. In a DUI case, the prosecution can show that the defendant blew a .08 on the breathalyzer test, but then the defendant has the opportunity to present defenses showing that he did not blow a .08 or that the .08 should be disregarded.

Without the Morissette decision, prosecutors could present all presumptions as conclusive and easily win many convictions. It underlines that the presumption of innocence is key to defending drivers in DUI cases.

Have you been charged with a DUI in Oklahoma and need help moving forward? Clint Patterson, Esq., of Patterson Law Firm, a former Tulsa prosecutor, uses his trial experience and expert-level knowledge of DUI science to defend drivers. He has the experience and the insight to evaluate the strengths and weaknesses of your case. To schedule a case evaluation, visit Patterson Law Firm online or call Clint’s office at (918) 550-9175.