Reporting from Sacramento -- The San Bernardino County district attorney’s office has filed criminal charges against a California lawmaker who attempted to take a loaded gun onto an airplane.

Tim Donnelly, a self-described tea party Republican from San Bernardino, was charged with carrying a loaded firearm in public without a concealed weapons permit and possessing a gun in an airport. Both offenses are misdemeanors, punishable by up to 18 months in jail and $2,000 in fines.

A vocal advocate for gun rights, Donnelly was detained by police at Ontario International Airport last month after security screeners discovered a loaded .45-caliber Colt Mark IV pistol and an ammunition magazine with an additional five rounds in his carry-on luggage.

The assemblyman, who was headed for Sacramento to attend the opening of the new legislative year, later characterized the incident as an “unfortunate mistake.” He told reporters he had forgotten to remove the gun from his briefcase after placing it there while working in his home garage.


On Friday, Donnelly issued a statement in which he said he had taken responsibility for “an innocent mistake.”

“I have fully cooperated with law enforcement officials and have been candid about this matter publicly,” he said. “I am deeply honored to represent the people of the 59th District and regret any inconvenience this has caused to those involved.”

The lawmaker told reporters last month that he regularly carried a firearm because he had received death threats since proposing to roll back state financial aid for illegal immigrants.

Assembly minority leader Connie Conway (R-Tulare) said Donnelly had the support of the GOP caucus: “Like anyone else, Tim is entitled to due process.... Assembly Republicans stand united with him in our legislative priorities of taxpayer protection and job creation.”


Donnelly, a former member of the volunteer border patrol group known as the Minutemen, was elected in 2010 on an anti-illegal-immigration platform.

michael.mishak@latimes.com