It looks like Blackwater guards won’t get their day in court after all. Efforts to prosecute the personnel of Blackwater, now known as Xe Services, of murder and other violent crimes in Iraq and Afghanistan are falling apart, apparently due to legal obstacles—mostly due to the difficulty of obtaining evidence in war zones. Most recently, the Justice Department said they will not prosecute a Blackwater armorer, Andrew J. Moonen, accused of killing a guard assigned to an Iraqi vice-president on Dec. 24, 2006, and officials said the case is being abandoned after results from an investigation were incomplete. Other high-profile cases have either failed to be brought to court or have resulted in mistrials or acquittals. Not only is evidence hard to gather in a war zone, but self-defense is often considered a more valid argument for crimes. Also adding to the complexity of the cases, until last year, foreign contractors had immunity from prosecution under Iraqi law, meaning the guards were operating in a legal vacuum.