The Georgia Supreme Court issued a ruling Monday that prevents prosecutors from using blood-alcohol test results against a driver accused of causing a fatal wreck.

The state's highest court ruled in favor of Harley Snyder, 31, who faces charges in Richmond County Superior Court that include vehicular homicide and driving under the influence.

Mr. Snyder wrecked his vehicle May 24, 2004, on Georgia Highway 10. His father-in-law, John E. Grant, who later died, was a passenger.

Because Mr. Grant didn't appear seriously injured and Mr. Snyder wasn't arrested that night, the officer had no right to obtain a blood sample without a search warrant, the court ruled.

The courts have narrowed the law governing implied consent in DUI cases since 2003.

If Mr. Grant had died the night of the accident, or if either he or Mr. Snyder had suffered obvious serious injury, an officer could have legally obtained the blood sample with his consent. If Mr. Snyder had been placed under arrest that night, the same would be true.

But that's not what happened. Neither man appeared injured, and Mr. Grant didn't die until 10 days after the accident. Mr. Snyder wasn't charged with any criminal offense until December 2004, when the blood test was completed.

"I don't like to count my chickens before they hatch, but I would think that this would end the case (against Mr. Snyder)," said his attorney, Brendan Fleming.