Police officers filled bins with more than 1,500 rifles and handguns outside the Los Angeles Memorial Sports Arena and the Van Nuys Masonic Temple, according to the Los Angeles Daily News.

Officials were mindful of both the massacre of students and teachers in Newtown, Conn., and a gunman's ambush that killed two firefighters in Webster, NY.

"All of us are still mourning the tragedy at Newtown, Conn.," said Mayor Antonio Villaraigosa. "So many young innocent children were mass-murdered in the way that they were, and now the assassination of two firefighters ... just breaks the heart of so many of us, particularly in this holiday season."

The anonymous buyback program allowed weapons to be turned in with no questions asked. Handguns, rifles and shotguns could be exchanged for $100 Ralphs grocery store gift cards. Assault weapons earned a $200 card.

The program, designed to get guns off the streets, usually is held in May. Villaraigosa decided to do it now in the wake of the Dec. 14 shooting rampage at Sandy Hook Elementary School.