NEW YORK (AP) - Mayor Michael Bloomberg has been a public face of gun control for years, but he's in a new, unsought spotlight after ricin-laced letters were sent to him and a group he helps lead.
The billionaire hasn't shied from using his political post and his personal fortune to push for gun control well beyond the city limits, garnering both plaudits and complaints that he's overreaching.
The poisoned letters to Bloomberg and the group Mayors Against Illegal Guns essentially threatened that "anyone who comes for my guns will be shot in the face," Police Commissioner Raymond Kelly said Thursday, shortly before the Secret Service disclosed that a similar missive was sent to President Barack Obama.
Bloomberg, speaking Friday on his weekly WOR Radio show, shrugged off any specter of danger.
"There's always threats, unfortunately. That comes with the job," the mayor said. "I trust the police department and I feel perfectly safe. I've got more danger from lightning than from anything else and I'll go about my business."
Bloomberg said Wednesday he wasn't inclined to back down.
"We're not going to walk away from those efforts," he said.
Fellow gun-control advocates deplored the letters, which arrived after Bloomberg played a prominent role in a now-stalled push for new firearms laws in response to the December school massacre in Newtown, Conn.
"The work Mayor Bloomberg does is vitally important to our cause, and our thoughts are with them this week," Dan Gross, president of the Brady Campaign to Prevent Gun Violence, said in a statement Thursday. He emphasized that the organization doesn't think the letter episode reflects the mass of Americans engaged in the issue.
Thanks to his office and pocketbook, Bloomberg has become a uniquely influential figure in the gun debate.
Vice President Joe Biden said in March that "there has been no support that has been more consequential" than Bloomberg's in the recent, White House-fueled press for new gun restrictions. And the National Rifle Association has made clear it sees Bloomberg as a leading foe, caricaturing him as an octopus on the cover of its magazine in 2007 and branding him an "evangelist for the nanny state."
Representatives for the NRA and another gun-rights advocacy group, the National Shooting Sports Foundation, didn't immediately respond to inquiries Thursday about Bloomberg.
As leader of the nation's biggest city, Bloomberg often emphasizes that he feels mayors are on the front lines of a fight against gun violence - and that killings and shootings have dropped to historic lows in New York during his nearly 12-year tenure. And he has pursued the fight elsewhere.
His administration has set up gun-buying stings in other states to highlight what it said were illegal sales, on the premise that many illicit guns in New York were bought elsewhere. The city has sued dozens of out-of-state gun dealers, resulting in court-appointed monitoring for many. One South Carolina dealer ended up pleading guilty to a federal weapons charge.
Bloomberg and Boston Mayor Thomas Menino founded Mayors Against Illegal Guns, which now includes more than 900 mayors. Financed partly by Bloomberg, the nonprofit group has spread its message through such means as a Super Bowl ad this year and a $12 million ad campaign less than two months later.
The Democrat-turned-Republican-turned-unaffiliated Bloomberg also has spent millions of dollars advancing his gun-control views through political contributions. In one example, his super PAC, Independence USA, spent more than $2 million on ads in the Democratic primary in a special congressional election in Chicago this year.
Bloomberg's favored candidate, then-Illinois state Rep. Robin Kelly, got the seat. And Bloomberg got some criticism that he was butting in where he didn't belong.
"You had someone from outside of the community determining what the issue was for Chicago and that district," Delmarie Cobb, a Democratic political consultant who worked with one of the other candidates, recalled Thursday. Her candidate, Alderman Anthony Beale, called for tougher gun laws himself during the campaign, but he also sought to focus on job growth and other topics.
Bloomberg said at the time he was just a concerned citizen who happens "to have some money, and that's what I'm going to do with my money - try to get us some sensible gun laws."
It wasn't the first time he'd been branded a gun-control interloper. Arizona Attorney General Tom Horne complained in 2011 that Bloomberg had overstepped his power in authorizing investigators to run a sting at a Phoenix gun show. Bloomberg's representatives noted that Arizona-based private investigators carried out the undercover operation.
Now, government investigators are working to figure out who sent the letters to Bloomberg and Obama.
The two directed at Bloomberg were postmarked from Shreveport, La., according to the postal workers' union, which cited information from a Postal Service briefing. The Shreveport postal center handles mail from Louisiana, Texas and Arkansas, Louisiana State Police spokeswoman Julie Lewis noted.
The White House and Bloomberg letters were intercepted at mail facilities before reaching the president or mayor. The third was opened by the mayors' group director, Mark Glaze.
Three New York police officers who examined the letter to Bloomberg experienced minor symptoms that have since abated, authorities said.
According to the Centers for Disease Control and Prevention, ricin is found naturally in castor beans. Exposure can cause difficulty breathing, vomiting and redness on the skin.
The letters were the latest in a string of toxin-laced missives, but authorities would not say whether the letters to Bloomberg and Obama were believed to be linked to any other recent case.
In Washington state, a 37-year-old was charged last week with threatening to kill a federal judge in a letter that contained ricin.
About a month earlier, letters containing the substance were addressed to Obama, a U.S. senator and a Mississippi judge. One of the letters was traced back to Tupelo, Miss., and a Mississippi man was arrested.