SAN DIEGO — The overturning of a Marine’s murder conviction on a judicial mistake is a stinging setback for the government and comes after a string of defeats in its prosecution of U.S. troops accused of killing unarmed Iraqis.

The case of Sgt. Lawrence Hutchins III represented one of the most significant murder convictions that the U.S. military had been able to get in its three biggest criminal cases to come out of the war. But a military appeals court dismissed that conviction Thursday because a military judge agreed to relinquish one of the lead defense attorneys for Hutchins before his 2007 court-martial.

Prosecutors must now decide whether to appeal, seek a new trial or let the Camp Pendleton Marine go free.

Hutchins is accused of leading a squad that included six other Marines and a Navy corpsman that allegedly dragged a 52-year-old man from his home in the Iraqi village of Hamdania in 2006, then killed him and then planted a shovel and AK-47 to make it appear as if he were an insurgent.

The case was particularly troubling because it demonstrated a serious breakdown in Marine Corps leadership and tied it to a heinous crime, said Lt. Col. Paul Hackett, a judge advocate in the Marine Corps reserve.

Hamdania was one the three top Iraqi war crimes cases the government has tried to prosecute. The other two highly visible Iraqi war crimes cases involved unarmed people killed while the Marines were in the midst of attacks.

“As an active reservist speaking to my peers, Hamdania is viewed as a very bad page in the Marine Corps,” Hackett said, adding that: “What’s really troubling about Hamdania is that there were multiple admissions to the general set of circumstances that spelled out an unlawful killing.”

While the reason the U.S. Navy-Marine Corps Court of Criminal Appeals threw out the conviction may seem “hyper technical,” Hackett said it also shows the military justice system is working by adhering strictly to the rules of law.

“A trial judge erred, they may have to try it again, and that’s a real problem, but that is also a testament to the fortitude and competency of the Navy-Marine Court of Appeals,” he added.

The other Iraqi war crime trials included eight Marines who were initially charged with murder or failure to investigate the killings of 24 Iraqis that occurred after a roadside bombing that killed a Marine. Six have had charges dropped or dismissed, and one was acquitted.

Marine Staff Sgt. Frank Wuterich, the squad leader, is scheduled to go to trial Sept. 13 on reduced charges of voluntary manslaughter in nine of the 24 deaths and other crimes in the November 2005 shootings in the town of Haditha.

Last year, a Marine accused of killing an unarmed Iraqi detainee during a 2004 battle to recapture the city of Fallujah pleaded guilty to dereliction of duty after the government dropped a murder charge as part of a plea agreement.

Lance Corp. Jermaine’s Nelson, who had his rank reduced from sergeant, was the last of the case’s three defendants. The other two were acquitted, one by a military jury and the other by a civilian court after he completed his military obligations and was beyond the reach of a court-martial.

While cases in civilian courts often hit similar legal snags and problems, experts say the nature of these cases make them inherently difficult to prosecute.

Military war cases are challenging because there are often no independent witnesses or autopsies of bodies. Prosecutors rely on the testimonies of fellow Marines, who also may skew the facts in the midst of a war.

“We go to war to kill the enemy, and there are terms and guidelines on what is a lawful killing and what is an unlawful killing, and then there is a gray area,” Hackett said. “It’s an extraordinarily complex area to define because it ultimately relies on subjective circumstantial evaluation of a Marine in a very difficult situation.”

What’s more, problematic troops are often given administrative discharges instead of sent to court-martial. As a result, charges have sometimes been dismissed on procedural errors because military lawyers lack the experience of these kinds of highly visible and contested trials, said Gary Solis, a former Marine Corps prosecutor and judge who teaches law of war at Georgetown University Law Center.

Mistakes also can be made by trial judges in military courts, just as such errors occur in civilian ones.

“You would hope in cases like this, the Marine Corps would cross its legal Ts and dot its legal Is, but you know sometimes that doesn’t happen,” he said. “Having been a military judge myself, I have sympathy. It’s just too bad in cases like these, but unfortunately we can’t say there are only mistakes in minor cases.”

Marine Corps Sgt. Lawrence Hutchins Photo by The Associated Press file

Denis Poroy

Marine Corps Staff Sgt. Frank Wuterich Photo by The Associated Press file

Chris Carlson