The pistol, she explained, was left to her husband by his father, who had been a police commissioner in the city of Torreón, Coahuila.

"A year ago, just before he died, he told us: ´Here it is, keep it as a memento. Hopefully you´ll never use it, but maybe one day it will serve you in some way,´ " she said. "And what do you know, it is serving us. I´m getting 500 pesos (US$45) for it! Now we can get our DVD player out of hock."

Delgado was participating in a program called "Swap Your Guns for Coupons," that went into effect on Jan. 28 in the state of Nuevo León. The effort, a cooperative effort between the state Secretary of Public Security and the federal Secretary of Defense, gives citizens 500 pesos worth of coupons, known as vales de dispensa, for each gun they turn in.

The coupons can be redeemed at supermarkets and department stores for foods or goods.

Similar gun exchange efforts have been held in other parts of the country. The Mexico City precinct of Álvaro Obregón, for example, held a swap in January called "Exchange Your Gun for a Computer," and violence-plagued cities like Tijuana and Culiacán have held events as well.

Though firearm sales and licenses are much more controlled in Mexico than in the United States, guns are still widespread here. Police here confiscate an average of 256 weapons per day from suspects, and newspapers are filled with accounts of violent shootouts and armed attacks. Gun exchanges have become one part of the ongoing effort to fight the proliferation of firearms.

The majority of the people who have participated in the Nuevo León campaign have been from lower-income groups. And while many of the participants interviewed expressed relief at getting a gun out of their house, most said that they were inspired to participate out of economic interests.

"I came for the coupons," said Ángel Segura Cayetano, 68. "I need money right now. I am a pensioner and I am just barely getting by."

But some professionals have taken part as well, like José Polendo, a chemical engineer, who came to the swap with his wife, who works as a teacher.

"I brought an old pistol that, in fact, is a memento from my grandfather," he said. "I´ve had it for 50 years, but it´s never been useful to me, nor will it. So now, if they´re going to give me 500 pesos for it, well, that will do well to buy some carne asada."

Professional or lower-middle class, the Nuevo León participants seemed to be primarily law-abiding citizens and likely not those who use their firearms to perpetuate crimes. This may be a result of the fact that in order to participate, citizens must give their names and answer questions about where they got their weapons.

Buying a weapon legally is extremely difficult in Mexico. The Secretary of Defense issues all gun licenses after a wait of one year or more, and they cost about US$1,900. Licenses must be renewed every two years, and there are fewer than 2,500 registered gun owners in the entire country.

Gun swap participants, however, are told they will not be subject to prosecution if the gun they turn in is unlicensed.