PORTLAND – The state supreme court Friday denied the appeal of a repeat drunken driver whose 15-year prison term for injuring a mother and daughter in a crash in Scarborough is thought to be the longest ever in a Maine OUI case.

The court upheld the conviction of Robert Pineo, 58, of two counts of aggravated assault, one count of aggravated OUI and two counts of driving to endanger for driving his pickup truck head-on into a car on the night of Aug. 21, 2000.

The collision injured Sarah Buckingham, the driver of the car, and left her mother, Diane Buckingham, with permanent injuries that resulted in numerous surgeries and multiple disabilities.

Pineo’s prison term is believed to be the longest ever imposed in Maine for a drunken driving case and is even longer than those handed down in manslaughter cases that involved drunken driving.

The Maine Supreme Judicial Court concluded that Pineo’s multiple convictions for the same criminal act did not run afoul of his constitutional protections against double jeopardy.

Because aggravated assault, aggravated OUI and driving to endanger each require proof of a factual element that the others do not, Pineo could be convicted of all three crimes, the justices concluded.

They also found nothing illegal in the imposition of consecutive sentences.

The court also brushed aside Pineo’s challenge to the admissibility of a test showing that his blood alcohol level was 0.16, or twice the legal limit.

The justices said the trial judge’s only error was his issuance of a stay on the six-year suspension of Pineo’s driver’s license until he gets out of prison.

In sentencing Pineo, Superior Court Justice Roland Cole cited his history of drunken driving and called him “a potential homicide waiting to happen.”