2014/12/24 Headlines: Missouri Police Kill Black Teen Near Ferguson; Protesters Defy NYC Mayor's Call for Halt to Protests Following Officer Murders; Family Calls for Federal Probe After Houston Officer Cleared in Fatal Shooting of Unarmed Black Man; FDA Eases Lifetime Ban on Blood Donations by Gay, Bisexual Men; Obama Admin Envoy for Guantánamo Closure Resigns; GOP Rep. Grimm Pleads Guilty to Tax Fraud, Won't Resign; Sony Gives "The Interview" Christmas Release at Independent Theaters; U.N. Arms Trade Treaty Takes Effect; U.S. Hasn't Ratified