San Jose Mayor Sam Liccardo is today proposing a city ordinance that would require firearm owners to either carry liability insurance or pay a fee to cover public costs of gun violence to the city.

Why it matters: San Jose is reeling from the Gilroy Garlic Festival shooting last month that killed 2 children and 1 adult and injured a dozen more. The city, the 10th-largest in the U.S., is the first to propose this kind of "harm reduction" measure to curb gun violence.

How it works: If approved by the city council, the measure would require San Jose gun owners to have private liability insurance.

If such insurance is not available, or if an individual is not able to purchase coverage, firearm owners could pay a fee intended to help cover the costs to city police and emergency services related to gun violence.

That payment would need to be protected with strict privacy standards, possibly using blockchain technology, to comply with California's state law that precludes local governments from establishing gun registries.

What they're saying: Insurance can incentivize safe behavior and discourage risky behavior, from purchasing a home security system to thinking twice about letting a teenager drive a car, Liccardo told Axios in an interview.

"Those are all decisions that are influenced in different ways by price signals in the insurance markets," he said. "In many cases, we can say insurance has saved thousands of lives because drivers recognize, for example, the benefit of having a discount for an airbag."

The intent of the harm-reduction model, he said, is to pull the gun debate out of the idealogical arena and "try to find ways we can reduce the harm of gun violence without infringing on recognized Second Amendment rights."

Gun insurance proposals have been unsuccessfully pitched before at both the national and state level, with several states proposing insurance requirements after the Sandy Hook Elementary massacre.

The other side: Opponents of the insurance measures say they infringe on Second Amendment rights by creating a new financial burden for gun owners. The insurance and firearm industries have argued in the past that property or casualty insurance does not cover intentional criminal behavior.

Liccardo makes a public health argument, pointing out that in addition to automobile insurance, the U.S. taxes tobacco consumption to discourage risky behavior and cover the public health costs generated by smoking-related illnesses and deaths.

Under his proposal, insurance would provide coverage for accidental discharge of the gun and for the intentional acts of third parties who steal, borrow or otherwise acquire the gun.

What's next: Liccardo's proposal will need to be approved by the city council, and he is starting conversations with other California mayors and state legislators.