Judge Everett Krueger on Wednesday followed the recommendation of the trial jury, which could have recommended life without parole for 54-year-old Gerald Hand.
Hand had said he would try to be a model inmate if sentenced to life in prison, and his son tearfully asked the jury to spare his father's life. "He's the only person I have left to guide me," said Robbie Hand, 25.
Hand was convicted Friday of killing his wife, Jill, 58, and friend Walter Welch, 55, last year at the couple's home north of Columbus.
Prosecutors also suspect Hand in the deaths of his first two wives, but he has not been charged. They said during the trial that Welch helped Hand kill his first two wives and Hand shot him to keep him quiet.
Hand said he shot Welch in self-defense because he believed Welch was an intruder who had shot his wife. He denied involvement in any of his wives' deaths.
Donna Hand, 27, and Lori Hand, 21, died in 1976 and 1979 at the same house in Columbus. Prosecutors said Gerald Hand collected insurance money after each death. A third marriage ended in divorce.
The jury found Hand guilty of aggravated murder, conspiracy to commit aggravated murder and escape. His attorneys have said they plan to appeal.