After 16 months of waiting, Robin Patterson still is not sure what she will say this week when she has the chance to confront the man charged in the death of her son, Lance Cpl. Kristopher Cody Warren.

“I have thought really long and hard about it,” said Mrs. Patterson, a Resaca, Ga., resident whose son was killed in November 2006 by a gunshot to the face. “I’m still so emotionally mixed in my heart, I just don’t know.”

Cpl. Douglas Michael Sullivan, 23, a Marine from Hamilton, Mass., is charged with manslaughter in Lance Cpl. Warren’s death. This week, at Camp Pendleton, Calif., attorneys, witnesses and family members will gather for either a general court-martial or, if a plea agreement is reached, a sentencing hearing, Mrs. Patterson said.

“We still don’t know if we’re going out for a sentencing or for a trial,” said Mrs. Patterson, who will leave today for California.

The court-martial has been scheduled and postponed several times over the last year, Mrs. Patterson said, and she was once within hours of leaving for California when she was told not to come. But she expects this week to be different, she said.

“They have assured me that it is going to happen,” Mrs. Patterson said. “I have a whole different feeling now than I ever have before.”

Lance Cpl. Warren worked as a radio operator in the Combat Operations Center at Forward Operating Base Trebil in western Iraq. On Nov. 9, 2006, just before midnight Iraq time, Lance Cpl. Warren and Cpl. Sullivan were completing a shift in the operations center, according to a stipulation of fact document signed by Cpl. Sullivan in August.

According to the document, Cpl. Sullivan picked up another Marine’s rifle from a rack, took the weapon off safety, sighted the scope on Lance Cpl. Warren’s face and pulled the trigger.

“When the weapon fired, it completely shocked me,” Cpl. Sullivan said in the statement. “I did not intend to shoot Lance Cpl. Warren. Lance Cpl. Warren and I were close friends.”

John Andrews, an attorney from Salem, Mass., who represents Cpl. Sullivan, said his client is “devastated” by what happened. He will be in California today ready for trial, Mr. Andrews said.

“I arrived ready for trial in November, when it was last scheduled, and the government continued the case,” he said.

Attorneys with the Marine Corps could not be reached for comment.

According to information from Camp Pendleton, Cpl. Sullivan faces up to 10 years in prison.

Lance Cpl. Warren’s father, Joe Warren, of Woodstock, Ga., said he is anxious to see the end of waiting for some kind of resolution in his son’s death. The repeated rescheduling of the court-martial has been stressful, he said.

“I’m kind of wanting to get it done,” said Mr. Warren, who also is scheduled to leave today for Camp Pendleton. “It just messes me up for a month or so every time. I just dread it.”

During sentencing, the Warrens will have a chance to talk about their son and show pictures and movies from his life, Mrs. Patterson said. She plans to bring photos of her son and DVDs of his performances as a drum major with the Gordon Central High School band.

But she knows that no matter what happens this week, she’ll come home with a heavy heart, she said.

“Part of me is happy that’s it’s finally going to come to an end, but there’s no winning on either side,” she said. “What I want, I can’t have back.”

* June 2005: Kristopher Cody Warren leaves for Marine Corps boot camp one week before his 18th birthday.

* May 2006: Lance Cpl. Warren leaves to train for deployment to Iraq.

* September 2006: Lance Cpl. Warren arrives in Iraq, along with 32 other Marines in the Chattanooga-based Mike Battery Reserve unit. He is the youngest in the group.

* Nov. 10, 2006: Lance Cpl. Warren, 19, is killed by a gunshot to the face.

* Nov. 27, 2006: Cpl. Douglas Michael Sullivan, of Hamilton, Mass., is charged with manslaughter Lance Cpl. Warren’s death.

* Today: A general court-martial of Cpl. Sullivan, 23, is scheduled to begin at Camp Pendleton, Calif.