WASHINGTON -- Senator Dianne Feinstein (D-Calif.) on Tuesday placed a hold on two controversial pieces of legislation that would force states that allow the concealed carrying of guns to recognize each other's permits.

Feinstein informed party leadership that she would oppose the quick passage of two concealed carry reciprocity bills that critics argue would cause a "race to the bottom" in terms of concealed weapon law in the United States. The senator cited the shooting of Trayvon Martin, an unarmed teenager killed in Florida, as one of the reasons she was applying the legislative brakes.

"Besides putting domestic violence victims in danger, the concealed carry reciprocity bills would also create potentially life threatening situations for law enforcement officers," Feinstein wrote in a letter to Senate Majority Leader Harry Reid (D-Nev.) and Senate Judiciary Committee Chairman Patrick Leahy (D-Vt.).

"In recent weeks, our nation has witnessed tragic gun violence in Sanford, Florida and in Oakland, California, which is only a short drive from my home. Notably, George Zimmerman, the man who shot and killed 17-year-old Trayvon Martin in Sanford, Florida, had been issued a concealed carry permit under Florida law, even though he had previously been subject to a court order for domestic abuse of his ex-fiancée. Congress should heed the warnings of law enforcement and not force states to recognize the permits issued to individuals by other states."

In putting a hold on both bills, the "National Right-to-Carry Reciprocity Act of 2012," and the "Respecting States' Rights and Concealed Carry Reciprocity Act of 2012," Feinstein is denying them the easiest avenue of passage: unanimous consent.

The hold does not eliminate the possibility of passing the bills through regular order, with 60-vote requirements to start and end debate. But it's unclear whether enough support actually exists in the Senate. Sen. Scott Brown (R-Mass.), for instance, has said he would oppose the first bill, which cleared the House of Representatives in November with 43 Democrats supporting it and only seven Republicans voting against it.

If, in fact, both bills stall in the Senate, it would constitute a rare defeat for the gun rights lobby, which has had a series of legislative wins on both the state and federal level. And for that, Feinstein's hold gave fellow gun control advocates a rare reason to gloat.

"We hear regularly that senators of both parties are getting tired of being ordered around by the gun lobby, and forced reciprocity is exhibit a," emailed Mark Glaze, the director of the group Mayors Against Illegal Guns. "It has nothing to do with the second amendment and everything to do with replacing individual state decisions about public safety with the NRA leadership's wish list."

READ FEINSTEIN'S FULL LETTER HERE: