Jurors on Thursday told 3rd District Court Judge G.D. Carey that they were sharply divided over a verdict.
Prosecutors say Bujak mishandled money from a contract to prosecute misdemeanors in Nampa.
Bujak, who acted as his own attorney, countered during his trial that money exceeding the amount necessary to pay his county staff to cover Nampa cases belonged to him.
With this deadlock, prosecutors must decide whether to abandon the case or try for a new trial.
Bujak faces 14 years in prison, if convicted.
He's facing other felony charges including grand theft at separate trials set for later this year.