Minnesotans accused of driving under the influence of alcohol (DUI) have the right to independently test the blood sample evidence taken by police. Should law enforcement refuse to release that sample on request, the state court of appeals ruled Monday that such conduct violates due process and merits exclusion of the blood evidence at trial.

In March 2010, David Hawkinson was arrested for DUI in the city of Plymouth. He consented to have his blood drawn and tested. The Bureau of Criminal Apprehension estimated Hawkinson's blood alcohol content (BAC) at 0.11, in excess of the legal maximum of 0.08. Within three months of the arrest, Hawkinson's attorney requested the blood, only to learn just before trial that it had been destroyed. A Hennepin County District Court judge ruled the evidence of the blood sample should be excluded because the bureau was unable to turn over the evidence.

State prosecutors appealed, arguing it was up to Hawkinson to prove the destroyed evidence would somehow have exonerated him. The three-judge appellate panel disagreed with the state.

"The right to determine whether evidence is 'favorable to an accused' does not belong to the state: the state may not determine what evidence is definitely, probably, or possibly not favorable and then destroy it after the accused has specifically and in writing requested that it be preserved without violating due process," the appeals court ruled. "Here, because there was no evidence other than the blood sample that respondent had driven with an alcohol concentration exceeding .08, the destruction of the blood sample was not harmless error."

The ability to independently test blood samples is important given the problems with breathalyzer machine calibration nationwide. In Washington, DC the city's attorney general admitted at least 300 drivers were prosecuted based on readings from faulty machines between 2008 and 2010. Another 82 drivers were falsely accused based on unreliable blood tests in Colorado Springs, Colorado's crime lab.

In Los Angeles, California attorney Lane Scherer defended a client accused of having a BAC of 0.15. According to Lawrence Taylor, author of DUI Blog, restesting the blood sample showed the a BAC was actually 0.13. As the client maintained his innocence, Taylor's law firm had a $1200 DNA test performed on the blood sample, which found the accused man was indeed innocent because the crime lab had mixed up the blood samples.

With the blood sample excluded, no case remains against Hawkinson. A copy of the ruling is available in a 75k PDF file at the source link below.