U.S. Marine Corps Commandant Gen. James Conway is deciding what to do with the dereliction of duty case against Lt. Col. Jeffrey Chessani, the Camp Pendleton officer accused of failing to order a full-scale investigation into the slayings of two dozen Iraqi civilians in the city of Haditha in 2005.

Conway got the case in late May, after the Marine Corps gave up its appeal of a military judge's ruling that unlawful command influence illegally tainted the case against Chessani.

The Marine Corps appealed that ruling on two occasions and was considering a third appeal before deciding to let Conway determine the next move in the Chessani saga.

"He (Conway) will consider the matter carefully," Maj. David Nevers at the Marine Corps' Pentagon headquarters said, adding there no was firm date for when Conway would announce his decision.

Conway's options include dropping the case entirely or appointing a new convening authority to consider whether a new investigation should be ordered. He also can pursue a non-criminal administrative action against Chessani, who commanded the 3rd Battalion, 1st Marine Regiment, at Haditha when the civilians were slain by Marines after a roadside bombing.

Chessani, 43, was charged with dereliction of duty in December 2006 after Marine prosecutors said he negligently failed to order a full-scale investigation into the killings. Chessani maintains he kept his superiors informed of the killings and was never directed to launch such a probe.

One of Chessani's attorneys, Brian Rooney, said the Colorado native is hoping the commandant ends the prosecution without any further action.

"He did nothing wrong and he's not willing to accept any administrative punishment," Rooney said. "But there are things the commandant can do, such as a order a letter be placed in his file, and Col. Chessani cannot refuse that."

Gary Solis, a military law expert who has closely followed the Chessani and other Haditha prosecutions, said he thinks the commandant should opt for dropping the case.

"This is a case whose time has passed," Solis said. "From the first time the military judge said unlawful command influence tainted the case, anything that follows in terms of a prosecution will be suspect."

The unlawful command influence ruling determined that a legal adviser for the prosecution should not have had any role in the case. The adviser, Col. John Ewers, had investigated each of the accused Marines and was listed as a prosecution witness.

His presence at meetings with a general overseeing the Haditha cases and prosecutors created an unacceptable perception of unlawful command influence, the military judge concluded.

Four officers and four enlisted men were charged with crimes at Haditha. In the more than two years since, three of the officers and three of the enlisted men have been exonerated by having charges being withdrawn or, in one case, a not-guilty finding at trial.

Besides Chessani, the only man still facing prosecution is Staff Sgt. Frank Wuterich, who led his squad in a search for those responsible for the bombing.

Wuterich is charged with nine counts of voluntary manslaughter. He has pleaded not guilty and, like Chessani, remains on duty at Camp Pendleton pending resolution of the case against him.

Chessani intends to retire from the Marine Corps if the charges against him are dismissed.

Call staff writer Mark Walker at 760-740-3529.