A Republican lawmaker is renewing his effort to allow concealed carry permits holders to carry guns into some public buildings.

The proposal comes from Sen. John Kavanagh, R-Fountain Hills, after a bill he pushed last year failed to pass. Efforts in previous years also failed.

Senate Bill 1243 would require operators of public establishments to allow permit-holders to carry their firearms unless the business employs security guards and has metal detectors at entrances.

Courtrooms, federal buildings, high schools and universities, and the Maricopa Medical Center would be exempt.

Kavanagh said Tuesday that people screened for weapons permits can be trusted in public buildings.

"There's no reason why people who have been screened and tested and are proficient can't carry guns in public buildings, when people are carrying guns almost everywhere else," Kavanagh said. "And criminals are already carrying guns in public buildings."

Democratic Sen. Steve Farley said there's plenty of buildings without screenings where guns should be banned, citing places such as the Department of Child Safety, where emotions can run high. He also said most gun owners don't believe looser gun laws are needed in Arizona.

He said having armed people in buildings will just make things more difficult for police if they are called to a building for an emergency.

"A good guy with a gun isn't something that law enforcement tells me is really easy to pick out," Farley said. "When they come onto a shooting scene, they don't know who's the good guy and the bad guy."

An analysis of last year's bill showed the costs to secure state buildings at up to $6 million a year and up to $13 million a year at Maricopa County facilities alone. More than 300,000 Arizona residents have a concealed weapons permit, although one isn't needed to carry a concealed gun.