In the most recent and closely watched case, the Justice Department on Monday said that it would not seek murder charges against Andrew J. Moonen, a Blackwater armorer accused of killing a guard assigned to an Iraqi vice president on Dec. 24, 2006. Justice officials said that they were abandoning the case after an investigation that began in early 2007, and included trips to Baghdad by federal prosecutors and F.B.I. agents to interview Iraqi witnesses.
The government’s decision to drop the Moonen case follows a series of failures by prosecutors around the country in cases aimed at former personnel of Blackwater, which is now known as Xe Services. In September, a Virginia jury was unable to reach a verdict in the murder trial of two former Blackwater guards accused of killing two Afghan civilians. Late last year, charges were dismissed against five former Blackwater guards who had been indicted on manslaughter and related weapons charges in a September 2007 shooting incident in Nisour Square in Baghdad, in which 17 Iraqi civilians were killed.
Interviews with lawyers involved in the cases, outside legal experts and a review of some records show that federal prosecutors have failed to overcome a series of legal hurdles, including the difficulties of obtaining evidence in war zones, of gaining proper jurisdiction for prosecutions in American civilian courts, and of overcoming immunity deals given to defendants by American officials on the scene.