The Tucson Police Department has destroyed 4,820 guns turned in by residents or seized from crime investigations since the beginning of 2013, city records show.

The figure is at the heart of a complaint made by state Rep. Mark Finchem, who is arguing Tucson is violating a 2013 Arizona law that requires the sales of otherwise legal guns obtained by law enforcement agencies.

Finchem filed his complaint using a new law signed by Republican Gov. Doug Ducey this year. SB 1487 says local governments that violate state laws lose their state-shared revenue if they don’t stop. Tucson received $172 million from the state last year.

Finchem argues the city’s policy is destroying valuable public property.

“The city of Tucson flagrantly violated state statutes and deprived the taxpayers of the opportunity to obtain a fair-market value of a public asset,” the Oro Valley Republican said in a news release, adding the guns should have been auctioned off to the highest bidder.

Tucson City Attorney Mike Rankin sent Arizona Attorney General Mark Brnovich, who is investigating Finchem’s complaint, a 16-page letter explaining why the destruction of city property does not fall under the legal control of the Legislature.

City officials said they are acting within their power to make decisions locally without outside interference, as allowed under City Charter rules.

“This is a matter of solely local concern in which the state Legislature may not interfere,” Rankin wrote in his letter to Brnovich. He said the laws cited by Finchem in his complaint do not apply to the city in this case.

The city has been destroying guns for more than a decade, Rankin noted.

Tucson Mayor Jonathan Rothschild said the complaint before Brnovich is a legal one, not a political decision by the city of Tucson.

Rothschild said SB 1487 challenges the city’s sovereign status.

Ken Strobeck, the executive director of the League of Arizona Cities and Towns, agrees with Rothschild.

“We think Senate Bill 1487 is probably the most offensive and improper overreact of state government into local affairs that I’ve ever seen in my career,” said Strobeck.

“With having the enormous threat of withholding state shared revenues, which is generally about 40 percent of a city’s operating budget as a hammer — it is simply a matter of saying ‘You do it my way or we issue this virtual death penalty.’”

City policies allow only for rifles that are not semi-automatic and shotguns to be sold at public auction. All handguns and semi-automatic rifles taken in by police are destroyed.

Roughly 86 percent of the guns that were disposed of in the last 3½ years were destroyed, according to documents provided by the Tucson Police Department. Of the remaining 14 percent, half were put up for sale at auction and half were kept for law enforcement purposes.

Guns largely came into the city’s possession as a result of criminal investigations, although they also could become city property if they were turned in by residents to be destroyed or if they were found by police and their owners could not be located.

Todd Rathner, a member of the National Rifle Association of America Board of Directors, said the city is picking and choosing which laws it wants to follow.

“They are willfully disobeying state law,” Rathner said.

He said the decision to destroy guns rather than auction them off has become political.

“They are making determinations based on a politicized description of a firearm,” Rathner said.

Police Chief Chris Magnus declined to comment on the case, citing pending litigation and deferred all questions to Rankin.

Contact reporter Joe Ferguson at jferguson@tucson.com or 573-4197. On Twitter: @JoeFerguson