Prosecutors say Andrew Cox pleaded guilty to attempted first degree battery, a Class C felony. He will no serve three years of supervised probation.
Investigators say Cox and Shirley Mugley planned to place a pipe bomb in her ex-husband's car last year.
Last month, Mugley pleaded guilty to conspiracy to commit capital murder. She was sentenced to 18 years in prison.
Prosecutors say Cox's cooperation with the investigation helped them build a case against Mugley.