Co-defendant Christopher Travis Baker, 30, was convicted by a jury in December and sentenced to life in prison plus 30 years.
Prosecutors said Baker ambushed Waldenville just after midnight, shooting and robbing him of $6,000 he was going to deposit for the restaurant.
Prince had a deal with prosecutors to testify at Baker's trial but refused to do so and forfeited a 17-year prison sentence. He told the judge he backed out of the agreement because he and his family had received threats.
Prosecutors said it was the first they had heard about Prince being threatened. They used Prince's testimony from Baker's preliminary hearing against the co-defendant at trial.
In that testimony, Prince said he stopped short of robbing Waldenville because he was afraid Waldenville would shoot him. He said Baker surprised the deputy from behind and shot him before he could draw his gun.