But a Gloucester County grand jury believed him, and now it's the officer who's facing charges.
The Washington Township officer, Joseph DiBuonaventura, was indicted Wednesday on 14 counts, all accusing him of making a bogus arrest of Moriarty on July 31 and lying to support his claims.
If the officer is convicted on all charges, including false swearing and falsifying evidence, he could be sentenced to decades in prison.
DiBuonaventura's lawyer, James Lynch, did not immediately return a call from The Associated Press on Thursday after the indictment was made public.
The officer was suspended without pay and charged by prosecutors last year. But Moriarty said in a statement Thursday that it's the indictment that validates him.
"I did nothing wrong that day. I was falsely arrested. My property was seized. My good name was tarnished," the Democratic lawmaker said. "I hope now that true justice can take place and my good name restored."
Moriarty says he did not have anything to drink the day he was arrested. Last year, he showed reporters a squad-car video of his arrest that he said showed he had done nothing wrong.
Before he entered politics, Moriarty was a Philadelphia television personality known for a consumer-affairs segment called "Can You Believe It?" He later became mayor of Washington Township.
His drunken-driving case has been put on hold while the case against DiBuonaventura moves ahead.