A federal appeals court on Monday once again decided to weigh in on an epic 12-year-old gun rights showdown over an Alameda County ordinance banning guns and ammunition on public property.

In a brief order, the 9th U.S. Circuit Court of Appeals agreed to rehear a legal challenge to the 1999 law, which restricts gun shows on county property, including Alameda County's fairgrounds. The order, which calls for an 11-judge 9th Circuit panel to hear the case, wipes out a ruling from May by three 9th Circuit judges who unanimously agreed to uphold the legality of the ordinance.

The development marks the latest twist in a long-running lawsuit pressed by gun show promoters Russell and Sallie Nordyke, who've enlisted gun rights groups to attack the law as a violation of their Second Amendment rights.

The 9th Circuit has ruled on the conflict several times, but the U.S. Supreme Court's rulings in recent years strengthening gun rights protections and limiting gun control laws elsewhere have continued to hang over the case.

In the May ruling, the 9th Circuit concluded that Alameda County's law did not trample on the right to bear arms to protect private property, saying it was justified for public safety reasons and limited to restricting gun shows on government property.

A majority of the 9th Circuit's full-time judges had to approve the decision to rehear the case with an 11-judge panel.

The Nordykes in the late 1990s successfully challenged a Santa Clara County restriction on gun shows at the county fairgrounds, and county officials abandoned efforts to enact an ordinance to ban them since that time.

Contact Howard Mintz at 408-286-0236.