Blackwater Worldwide security guard Nick Slatten (C) and attorneys leave the federal courthouse after being arraigned with 4 fellow Blackwater guards on manslaughter charges for allegedly killing 14 unarmed civilians and wounding 20 others in a 2007 shooting in Baghdad, in Washington in this January 6, 2009 file photo. A federal judge threw out all charges on December 31, 2009 against five Blackwater Worldwide security guards accused of killing 14 Iraqi civilians in 2007, saying the U.S. government had recklessly violated the defendants' constitutional rights. Picture taken January 6, 2009. REUTERS/Jonathan Ernst/Files (UNITED STATES - Tags: CRIME LAW POLITICS CIVIL UNREST) 

Former Blackwater Worldwide security guard Dustin Hard arrives with lawyer David Schertler at the U.S. District Court before surrendering to authorities in Salt Lake City, Utah, in this December 8, 2008 file photo. A federal judge threw out all charges on December 31, 2009 against five Blackwater Worldwide security guards accused of killing 14 Iraqi civilians in 2007, saying the U.S. government had recklessly violated the defendants' constitutional rights. Picture taken December 8, 2008. REUTERS/Chris Detrick/Files (UNITED STATES - Tags: CRIME LAW CIVIL UNREST POLITICS) 

Blackwater Worldwide security guards Donald Ball (2nd L) and Dustin Heard (R) leave the federal courthouse with their legal team and supporters after being arraigned with three fellow Blackwater guards on manslaughter charges for allegedly killing 14 unarmed civilians and wounding 20 others in a 2007 shooting in Baghdad, in Washington January 6, 2009. REUTERS/Jonathan Ernst (UNITED STATES) 

Blackwater Worldwide security guards Donald Ball (L) and Dustin Heard (2nd R) leave the federal courthouse with their supporters after being arraigned with 3 fellow Blackwater guards on manslaughter charges for allegedly killing 14 unarmed civilians and wounding 20 others in a 2007 shooting in Baghdad, in Washington, January 6, 2009. REUTERS/Jonathan Ernst (UNITED STATES) 

Blackwater Worldwide security guards Evan Liberty (L) and Dustin Heard (R) leave the federal courthouse with their legal team and supporters after being arraigned with 3 fellow Blackwater guards on manslaughter charges for allegedly killing 14 unarmed civilians and wounding 20 others in a 2007 shooting in Baghdad, in Washington, January 6, 2009. REUTERS/Jonathan Ernst (UNITED STATES) 

Blackwater Worldwide security guard Nick Slatten (C) leaves the federal courthouse after being arraigned with 4 fellow Blackwater guards on manslaughter charges for allegedly killing 14 unarmed civilians and wounding 20 others in a 2007 shooting in Baghdad, in Washington, January 6, 2009. REUTERS/Jonathan Ernst (UNITED STATES)