A military appeals court on Friday will hear arguments on why a judge dismissed charges against the highest-ranking Marine Corps officer charged in connection with the deaths of two dozen civilians in Haditha, Iraq, in 2005.

In June, military judge Col. Steven Folsom dismissed two counts of dereliction of duty against Camp Pendleton's Lt. Col. Jeffrey Chessani for Chessani's alleged failure to order a full-scale investigation into the killings in the wake of a roadside bomb.

The judge ruled a senior legal adviser to then-Lt. Gen. James Mattis, who was overseeing the Haditha prosecutions at Camp Pendleton, should not have had any role in shaping the case.

The adviser, Col. John Ewers, had been one of the military's initial investigators into the killings and is a potential prosecution witness. The judge ruled Ewers' mere presence at meetings between Mattis and prosecutors created an unacceptable perception of "unlawful command influence" in the general's decisions.

When he ordered the charges dismissed, Folsom said the Marine Corps could refile the case but said it would have to appoint a new investigating officer and a new convening authority.

Prosecutors opted to appeal.

The Marine Corps argues that Mattis, who has since been promoted to a four-star general and is no longer overseeing the Haditha case, was never unduly influenced.

"There is no evidence that Gen. Mattis relied on Col. Ewers for any information, opinions or legal advice," the Marine Corps says in its appeal. "Instead, the record shows Gen. Mattis to be an independent commander highly unlikely to be prone to manipulation by his staff officers."

In their response to the appeal, Chessani's attorneys contend Mattis' testimony was "self-serving" and that unlawful command influence has permeated the Haditha prosecutions "like a cancer affecting every aspect of this case from discovery to witnesses."

One of those attorneys, Brian Rooney, said Monday that the decision by the Navy-Marine Corps Court of Appeals in Washington following Friday's hearing could further be appealed to the Court of Appeals for the Armed Forces. Any appeal beyond there would go before the U.S. Supreme Court.

"This probably will not be the last appeal in this case," Rooney said. "But our hope is that someone will pull back the reins on this case because it has been politically motivated since the beginning."

Chessani and the man who led his troops in the slayings, Staff Sgt. Frank Wuterich, are the only remaining defendants among four officers and four enlisted men charged with wrongdoing at Haditha. Charges were dismissed or withdrawn against all the others following investigative hearings.

Wuterich, who faces multiple counts of manslaughter and related offenses, contends the civilians died as he and his men searched for their attackers after the bombing that killed one Marine and injured two others.

That case is on hold pending a decision by the Court of Appeals for the Armed Forces on whether the military judge in his case should review non-broadcast portions of a CBS television "60 Minutes" interview of Wuterich that prosecutors contend could include incriminating material.

The judge in Wuterich's case ruled the effort a "fishing expedition" when he sided with CBS earlier this year in denying access to those tapes.The Marine Corps' appeal of that ruling was heard last month by the five civilian judges who comprise the Court of Appeals for the Armed Forces and a decision is pending.

Numerous media groups sided with CBS in contesting the Marine Corps' appeal. The media groups contend the non-broadcast material is protected under the First Amendment from disclosure to prosecutors. A ruling to the contrary could set up a larger battle on First Amendment issues.

Wuterich and Chessani, who have each pleaded not guilty, remain on duty at Camp Pendleton working in administrative jobs.

Contact staff writer Mark Walker at (760) 740-3529 or mlwalker@nctimes.com.