Mayor Luke Ravenstahl allowed a city gun control bill to become law without his signature.

In a letter to council, Mr. Ravenstahl said the bill will be unenforceable and pre-empted by state law, but he supports efforts to stem stolen gun trafficking.

On Dec. 2, City Council voted 6-1 to approve legislation giving gun owners 24 hours to call police after they learn a firearm is missing. They would face a $500 fine if they do not report it, plus a $1,000 fine and possible prison time for a second non-report.

The bill is intended to deter straw purchasers from selling guns to criminals. When guns are traced back to them from crime scenes they routinely say they were lost or stolen. City Police Chief Nate Harper supported the legislation but his boss, Mr. Ravenstahl, did not.

"I appreciate council's fervor and creativity in attempting to craft legislation that would not be subject to the pre-emption hurdles. However, I cannot agree that our ordinance, as written, would be enforceable. Accordingly, I will not be signing it," he wrote.