Criminal District Court Judge Frank Marullo hung onto a majority vote Tuesday night, narrowly avoiding a Dec. 6 runoff for a new term in a judgeship he’s held for 40 years, even as the defeat of a statewide amendment to remove the mandatory retirement age for judges threatens to spark a new legal battle to keep him from ever starting his new term.

With all precincts reporting, Marullo took 51.3 percent of the vote. Former Orleans Parish prosecutor Graham Bosworth and attorney Marie Williams each had 24 percent, with Williams ahead by 79 votes.

Meanwhile, former state and federal prosecutor Byron C. Williams scored a convincing win over Municipal Court Judge Paul Sens in the two-man race for the vacant Section G seat at Criminal District Court. Williams won with 67 percent of the vote.

They were the only contested races among the 13 judgeships up for grabs this year in the criminal courthouse at Tulane Avenue and Broad Street.

Marullo, the longest-serving judge in Louisiana, defended the Section D seat in his first challenge since 1996. But his victory may only mark the start of a fight to take the bench for a new six-year term come Jan. 1.

Marullo was keeping one eye Tuesday night on his Section D race and the other on a statewide vote on whether to abolish a constitutionally mandated retirement age for judges, currently set at age 70.

Marullo claims he falls under the 1921 Constitution, which set the mandatory retirement age at 75 when then-Gov. Edwin Edwards first appointed Marullo to the bench in 1974, and not under the current Constitution, which took effect shortly thereafter.

Marullo, however, turns 75 on Dec. 31, raising a legal question on whether he can take the bench even under the former age limit. Recent court rulings allowed Marullo to stay in the race but were silent on his right to assume office.

The constitutional amendment to remove the age limit might have rendered that issue moot, but it failed resoundingly, with 58 percent of statewide voters rejecting it.

As a result, Marullo’s claim to another term figures to face a renewed legal attack.

Similar vagaries didn’t accompany the race to replace Criminal District Court Judge Julian Parker, who has stepped aside after 17 years on the Section G bench. Byron C. Williams dominated Sens.

Williams, 60, who most recently served as executive counsel to the president of Southern University, was an assistant district attorney in Orleans Parish from 2003 to 2008 and before that served as a federal prosecutor.

Active as a football official with the New Orleans Recreation Development Commission, he campaigned on a platform to run an efficient docket and partner with NORDC and community groups to try to stanch a tide of criminal activity in the city.

He also pledged not to hire family members to work for his court section — a swipe at Sens, who was the subject of a 2012 report by New Orleans Inspector General Ed Quatrevaux’s office criticizing the employment of 18 Sens family members at Municipal Court. Sens also faced negative publicity surrounding allegations of domestic violence from both sides in his ongoing divorce with his wife, Ann Sens.

He will remain on the bench at Municipal Court, where his term ends in 2020.

For Marullo, his victory ends a race packed with controversy and legal wrangling.

Bosworth, 36, initially said he got in the race only after consulting with Marullo, who at the time didn’t think he could legally run. Bosworth supporters then launched a failed bid to get Marullo tossed from the race, arguing in vain that he should be disqualified because of his age.

Meanwhile, Williams 43, threw a wrench into the campaign when she tape-recorded a September lunch meeting with Marullo in which he agreed to back her for a magistrate commissioner’s post, assuming she would get out of the race.

Follow John Simerman on Twitter, @johnsimerman.