CAMP PENDLETON -- A Marine officer and an enlisted man have been ordered to trial for their roles in the slayings of 24 Iraqi civilians in Haditha in 2004 and its aftermath, Marine Corps officials announced Friday afternoon.

Lt. Gen. James Mattis ordered Lt. Col. Jeffrey Chessani and Lance Cpl. Stephen Tatum to trial by courts-martial.

Tatum faces trial on charges of involuntary manslaughter, reckless endangerment and aggravated assault. Charges of murder and negligent homicide against him were dismissed.

Chessani will be tried for dereliction of duty and violation of a lawful order.

Both men can ask for a military jury that consists of one-third of their peers or trial by judge. They are the first of eight men originally charged to be ordered to trial.

A decision on what will happen to the enlisted man who faces the most murder counts, Staff Sgt. Frank Wuterich, is pending.

Tatum has acknowledged that he killed civilians, doing so "because of his training and the circumstances he was placed in, not to exact revenge and commit murder," Lt. Col. Paul Ware wrote in his recommendation earlier this year that he not face court-martial.

One of Tatum's attorneys, Kyle Sampson, said he was disappointed Mattis did not follow Ware's recommendation.

"Lance Cpl. Tatum did not commit any crime," he said. "We will take the fight to the courtroom. We will vigorously challenge the government's case and nothing will be left undone in defense of this fine young Marine."

Sampson also said that by prosecuting Tatum, the "success of future infantry combat operations is at stake."

Chessani was relieved of command when the battalion returned from Haditha last April.

One of Chessani's attorneys, Brian Rooney, said he and his client were disappointed, but not deterred. "We believe this decision will have a permanent, negative impact on Marine Corps trust tactics up and down the chain of command," Rooney said. "We welcome the chance to try the case before a jury of Lt. Col. Chessani's peers."

The Haditha case is one of the largest prosecutions of U.S. troops since the March 2003 invasion of Iraq. The incident has mixed domestic war politics with the fog of war and the rules of engagement, spawning two massive investigations and a series of hearings at Camp Pendleton over the last several months.

"This demonstrates that Gen. Mattis has a mind of his own when it comes to making a decision and that the recommendations of the hearing officer are just that -- only recommendations," said Gary Solis, a former Marine Corps judge and prosecutor, adding that he believes Mattis has been fair in deciding to withdraw charges against some of the others accused. "The circumstances of the incident -- combat under fire -- have played a significant role, and he has given the benefit of the doubt to some of those men."

The Iraqis were killed after a roadside bomb destroyed a Humvee, killing one Marine and injuring two others on the morning of Nov. 19, 2005.

Several children and women were among the dead.

Chessani and three other officers in the chain of command at Haditha were charged with dereliction of duty and related offenses for failing to order an immediate, full-scale investigation.

Two of the officers, Capts. Randy Stone and Lucas McConnell, subsequently had their charges dismissed. A hearing for the remaining officer, 1st Lt. Andrew Grayson, is pending.

The killings occurred as Wuterich led his Kilo Company squad from the 3rd Battalion, 1st Marine Regiment in an assault in response to the bombing in the early morning hours of Nov. 19, 2005.

Nineteen Iraqis were killed inside or near three homes that Wuterich and his men stormed in search of the bomber and other insurgents.

Five Iraqi men who emerged from a car that drove up moments after the bombing were killed by Wuterich and another man originally charged in the case, Sgt. Sanick Dela Cruz.

Wuterich later told authorities he believed the Iraqis in the car were tied to the attack and presented a threat.

Wuterich was charged with 17 of the deaths. Ware also presided over his hearing and has recommended 10 of the murder charges be dropped and that Wuterich be tried on seven counts of negligent homicide in the deaths of five children and two women.

Ware also said that even if Wuterich is ordered to trial, he doubts a military jury will see or hear evidence sufficient to convict.

In April, charges against Dela Cruz were withdrawn in exchange for his testimony.

Charges against Lance Cpl. Justin Sharratt were dropped by Mattis in August, who issued a lengthy statement at the time saying there was insufficient evidence and that Sharratt had done his best in trying to determine friend from foe at Haditha.

Sharratt, who was charged with three counts of murder, told authorities he believed the men he killed were preparing to fire at him.

Last month, Mattis was instrumental in career-ending letters of censure being issued by the secretary of the Navy to Marine Maj. Gen. Richard Huck and two colonels also at Haditha who failed to order an investigation. None of those men was charged criminally.

Mattis has been the convening authority over the Haditha case in his role as head of Marine Corps forces in the Middle East, a role he is about to relinquish for a new assignment and promotion to four-star general.

His replacement, Lt. Gen.-nominee Samuel Helland, will assume the role of convening authority, a sweeping power granted commanding officers under the Uniform Code of Military Justice.

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