NEWARK, NJ - FEBRUARY 22:  Shell casings collected from crime scenes pile up in the Newark Police Department's Ballistic Laboratory which hosted a gun buy-back on February 22, 2014 in Newark, New Jersey. As of Saturday, the two day gun buy-back resulted in dozens of rifles, pistols and other weapons being surrendered to the police department for a cash reward. The program is partnered with "Jewelry for a Cause", a company that turns destroyed weapons into jewelry whose profits are used to fund future gun buy-back and amnesty programs in Newark and across the nation.  (Photo by Spencer Platt/Getty Images)