The panel cited the Second Amendment, and extensively referred to U.S. Supreme Court rulings that struck down handgun bans in Chicago and Washington.
"We are called upon to decide whether a responsible, law-abiding citizen has a right under the Second Amendment to carry a firearm in public for self-defense," the majority opinion said.
"California generally prohibits the open or concealed carriage of a handgun, whether loaded or unloaded, in public locations. ... Nonetheless, one may apply for a license in California to carry a concealed weapon in the city or county in which he or she works or resides. To obtain such a license, the applicant must meet several requirements. For example, one must demonstrate 'good moral character,' complete a specified training course and establish 'good cause'" -- in other words show some threat.
California law delegates the power to issue a written policy on concealed-carry to each county and city.
When a group in San Diego was denied permits because individuals could not demonstrate a specific threat, they filed suit. However, a federal judge ruled against them.
The appeals panel majority reversed.
"The Second Amendment secures the right not only to 'keep' arms but also to 'bear' them -- the verb whose original meaning is key in this case," Circuit Judge Diarmuid O'Scannlain, a Ronald Reagan appointee, said in the majority opinion.
"Undoubtedly some think that the Second Amendment is outmoded in a society where our standing army is the pride of our nation, where well-trained police forces provide personal security and where gun violence is a serious problem," the opinion said. "That is perhaps debatable, but what is not debatable is that it is 'not the role of this [Supreme] Court [or ours] to pronounce the Second Amendment extinct.' Nor may we relegate the bearing of arms to a 'second-class right, subject to an entirely different body of rules than the other Bill of Rights guarantees that we have held to be incorporated into the due process clause.'"
The opinion said the judge "erred in denying the applicant's motion for summary judgment on the Second Amendment claim because San Diego County's 'good cause' permitting requirement impermissibly infringes on the Second Amendment right to bear arms in lawful self-defense."
There was no immediate word on whether the state would ask the full 9th U.S. Circuit Court of Appeals to rehear the case, or ask the U.S. Supreme Court for review.