NEW ORLEANS (AP) — Richard "Rick" Tonry, a lawyer and former congressman who served a prison term for violating federal campaign laws, has died. He was 77.

Richard Tonry II said his father died Tuesday of natural causes at his farm in Lumberton, Miss.

Tonry, a Democrat, was elected to Congress in 1976 but resigned four months later amid a federal investigation of vote-fraud allegations in St. Bernard Parish, a New Orleans suburb. He later pleaded guilty to misdemeanor charges stemming from the probe and served a six-month prison term.

"That was over 30 years ago and it certainly didn't define the person he was," his son said Friday.

Tonry later ran for a seat in the state House of Representatives after a court-ordered ban on engaging in political activity expired, but he finished last in a four-candidate race.

Tonry also ran for a St. Bernard Parish judgeship in 1999 but withdrew from the race before the election. Before he dropped out, Tonry told The Times-Picayune that he didn't see how his prison stint should preclude him from serving as a judge.

"If you're going to hold a misdemeanor conviction against me after 23 years, that's a person's choice," he said. "My integrity as a lawyer has never been questioned. Anyone who has any doubts about that, just ask their own lawyers about my reputation as a lawyer."

Tonry's legal troubles didn't end with the case that sent him to prison. He was convicted of conspiring to bribe a Chitimacha Tribe chairman in Louisiana to sign a contract for bingo parlors, but the 5th U.S. Circuit Court of Appeals threw out his convictions in 1988. The appeals court ruled that bribing the tribe chairman wasn't a crime under the Louisiana Commercial Bribery Statute.

"The bribing of anyone is certainly ethically and morally repugnant. However, in this case, it was not illegal," the court's majority opinion said.

Tonry spent seven years as a Jesuit seminarian before he decided to practice law. He was a founder of a Chalmette law firm that specialized in criminal defense and personal-injury cases.

"He has fought for individuals' rights and helped a lot of people over the years, touched a lot of people's lives," his son said.

A fan of Zorro, the fictional swashbuckling hero depicted in novels, television shows and movies, Tonry had a "Z'' tattooed on one of his ankles.

"I think he felt it reminded him every day to help those who couldn't help themselves," his son said.