Arizona law already allows gun owners to keep unloaded firearms in their cars when they park on school grounds.

But some Second Amendment-loving state lawmakers say that doesn't go far enough: They're pushing a bill to allow parents to store loaded guns in vehicles parked on school property.

House Majority Leader Warren Petersen said he proposed House Bill 2693 after the National Rifle Association approached him with concerns about the existing law.

Petersen, R-Gilbert, said the concern is that law-abiding parents could inadvertently break the law if they don't stop and unload their guns every time they drop off or pick up their kids from school.

“We have mothers, we have fathers that carry weapons in their car," he said during a hearing Wednesday. “People just aren't even aware of this."

The House Committee on Public Safety voted 4-3 to pass the bill Wednesday. It passed along party lines, with Republicans in support. It now goes to the full House for a vote.

Democrats on the committee voted "nay" without commenting.

Volunteers with Moms Demand Action for Gun Sense in America, a national advocacy group, testified against the bill, calling the current ban a "common sense" measure to keep kids safe.

"The bottom line is this: the presence of a gun increases the risk posed to children," said Suzanne McCormick-Fulton, a volunteer with Moms Demand. "The solution to keeping our kids safe isn't more loaded guns on school grounds, where kids go to learn and grow."

Gun-safety advocates warn that guns stored in vehicles are often the most popular targets for thieves.

Thousands of guns reported stolen from cars in Phoenix

According to a 2016 report from Everytown For Gun Safety, Phoenix police received reports of 4,664 guns stolen from vehicles between 2005 and 2014. Nationwide, a fifth of stolen guns are taken from vehicles.

McCormick-Fulton said the bill ignores "legitimate public-safety concerns," including the risk that loaded guns will be taken from cars.

Under existing Arizona law, it's illegal to carry a firearm on the grounds of a public K-12 school, with a two key exceptions for civilians:

One exception permits adults to store unloaded guns in their vehicles when they park on school campuses, as long as the firearm is kept out of sight and the vehicle remains locked.

A second exception exists for firearms "for use on the school grounds in a program approved by a school."

Committee Chairman Kevin Payne, R-Peoria, said he himself has accidentally broken the law by taking a loaded gun onto a school campus when he has picked up his children.

"Didn't know I was breaking a law," he said, "so let's get rid of an unnecessary law."

Reach the reporter at dustin.gardiner@arizonarepublic.com or 602-444-2471. Follow him on Twitter: @dustingardiner.