Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer sits next to a stack of rifles during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer adds a rifle to a stack of turned in guns during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: San Francisco police officers inspect guns that are being turned in during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

A stack of rifles is seen during a gun buy back program on December 15, 2012 in San Francisco. (Justin Sullivan/Getty Images)

SAN FRANCISCO, CA - DECEMBER 15: A stack of rifles is seen during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: People wait in line to turn in firearms during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer documents a rifle that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer inspects a rifle that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer documents a rifle that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: San Francisco police officers document guns that are being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: San Francisco police officers document guns that are being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: San Francisco police officers inspect a gun that was surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer inspects a gun that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: People wait in line to turn in firearms during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

A San Francisco police officer inspects a rifle that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco. (Justin Sullivan/Getty Images)

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer inspects a rifle that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer documents a gun that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

Bullets and a clip from a gun that was surrendered sit on a table during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

SAN FRANCISCO, CA - DECEMBER 15: Bullets and a clip from a gun that was surrendered sit on a table during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer inspects a gun that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer inspects a rifle that is being surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: A San Francisco police officer adds a rifle to a stack of surrendered guns during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

Weapons surrendered during a gun buyback program on December 15, 2012 in San Francisco. (Justin Sullivan/Getty Images)

SAN FRANCISCO, CA - DECEMBER 15: Guns sit in a box that were surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

Guns sit in a box that were surrendered during a gun buy back program.

SAN FRANCISCO, CA - DECEMBER 15: Guns sit in a box that were surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: Guns sit on a table that were surrendered during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)

Anonymous Gun Buy Back Program In San Francisco

SAN FRANCISCO, CA - DECEMBER 15: People wait in line to turn in firearms during a gun buy back program on December 15, 2012 in San Francisco, California. The San Francisco police department held a one-day gun buy back event that paid $200 per gun turned in. A better than expected crowd resulted in payback money running out and vouchers were issued to collect money within a week. Over 200 guns were collected. (Photo by Justin Sullivan/Getty Images)