Police officers handed out $200 grocery store gift cards to people who turned in an automatic weapon, and $100 gift cards to those who provided a handgun, rifle or shotgun.

Los Angeles has held an annual gun buyback since 2009, and similar events have been organized in years past in several other cities, including Detroit and Boston. Police in San Diego had a buyback earlier this month.

Some experts say the buybacks have little effect in reducing gun violence, but Villaraigosa touted the buyback program as one step that can be taken in response to the Sandy Hook Elementary School shooting in Newtown, Connecticut, on December 14 that claimed the lives of 20 children and six adult staff members.