A federal judge sentenced former Kauai physician Harold C. Spear III today to 12 and a half years in prison for unlawfully prescribing powerful pain medication to people here and on the mainland based solely on telephone conversations with them.

U.S. District Judge David A. Ezra ordered Spear, 60, to begin serving his 151-month prison term immediately because he feels Spear poses a substantial risk of fleeing due to his age, length of sentence and prior behavior.

Spear also faces sentencing in state court next week for pre-signing hundreds of blank prescription forms.