Steve Curtis, a former chairman of the Colorado Republican Party, faces up to three years in prison after being convicted Thursday of voter fraud and forgery for signing his ex-wife’s ballot during the 2016 election, prosecutors say.

The 58-year-old, who also was a KLZ radio host, was charged in February after authorities say DNA evidence and handwriting analysis linked him to the ballot of his ex, Kelly Curtis.

The Weld County District Attorney’s Office says court testimony during Curtis’ trial revealed that Kelly Curtis had moved to Charleston, S.C., in December 2015. When she called the county’s clerk and recorder to get her mail-in ballot, she was told she had already voted.

Prosecutors found Curtis forged his ex-wife’s name on her ballot and mailed it in.

Curtis claimed during the trial that he signed her ballot while he was suffering from a middle-of-the-night diabetic episode and then unknowingly mailed it in the next day, according to prosecutors and The Greeley Tribune.

Curtis’ attorney claimed his client “has a notoriously bad history of monitoring and controlling his blood sugar,” according to the newspaper.

But Deputy Weld County District Attorney Tate Costin told jurors Curtis “knew exactly what he was doing,” according to a news release.

The Tribune reports members of a Weld County jury deliberated for about four hours before returning their verdict against Curtis, which could also leave him with a sentence of probation.

“Voting is one of the most important rights we have as American citizens, and the defendant deliberately stole that right away from Ms. Curtis,” District Attorney Michael Rourke said in a written statement. “He saw an opportunity to vote twice in one of the most important presidential elections in recent history and intentionally defrauded our system.”

Former GOP chairman Steve Curtis Guilty of Forgery & Voter Fraud #kdvr pic.twitter.com/rBKg52HktU — Rob Low (@RobLowTV) December 7, 2017

Rourke added: “No matter the political party you belong to, we must always stand up to those who strip away the rights of others.”

Curtis, who was the state’s GOP chairman in the late 1990s, is scheduled for sentencing on Jan. 26.