LUDOWICI, Ga. (AP) -- Georgia prosecutors will seek the death penalty against three Army soldiers accused of killing a former serviceman and his girlfriend to protect an anti-government militia group, officials said Thursday during tense court hearings in which one victim's stepfather was tackled and handcuffed as he tried to rush the defense table.

Pvt. Isaac Aguigui, Pvt. Christopher Salmon and Sgt. Anthony Peden -- all active-duty soldiers stationed at Fort Stewart -- are each charged with 13 counts including malice murder, felony murder and illegal gang activity in the Dec. 4 slayings.

The victims, former soldier Michael Roark and his 17-year-old girlfriend, Tiffany York, were shot in the head in the woods of rural Long County near Fort Stewart in southeast Georgia. Fishermen found their bodies the day after they were killed.

"I want them gone. I want all of these individuals to disappear," said Nicholas Lee York, the slain girl's older brother, who applauded the decision to seek death for the soldiers. "They took something irreplaceable from me."

The case took a stunning turn at an earlier hearing Monday when prosecutors told a Superior Court judge the accused soldiers belonged to an anti-government militia operating within the U.S. military that had stockpiled at least $87,000 worth of guns and bomb components. They said the group had a range of plans -- from bombing a park fountain in nearby Savannah to poisoning apple crops in the state of Washington -- and its ultimate goal was to overthrow the U.S. government and assassinate the president. However, President Barack Obama was not mentioned by name as their target.

Atlantic Judicial Circuit District Attorney Tom Durden cites domestic terrorism as an aggravating factor that warrants the death penalty. However, all charges against the soldiers relate directly to the killings. No charges have been filed in state or federal court accusing the three suspects of terrorist plots or acts.

"Sometimes some of these things don't fit neatly into our state laws," Durden said after court when asked about the absence of terrorism-related charges. "We're going forward with what we feel comfortable with."

Because they now face capital charges, all three soldiers will need to have new attorneys appointed with death penalty experience. They won't be arraigned or asked to enter pleas until that happens.

"At this point, there has been no evidence presented to prove anything," said Keith Higgins, an attorney who represented Aguigui in court Thursday. "The fact that certain statements are being made does not necessarily mean these allegations are true."

Salmon's wife, Heather Salmon, has also been charged with murder and other counts. She did not appear in court Thursday and Durden said he will not seek the death penalty for her.

Authorities took extra precautions Thursday as the accused soldiers, in shackles and jailhouse jumpsuits, were brought before the judge for a preliminary hearing. The defendants were brought to the courthouse one-at-a-time, with their hearings scheduled an hour apart. Deputies armed with assault rifles walked in front of and behind them.

Relatives of both victims have been seething since Monday's hearing after a fourth soldier who says he witnessed both slayings testified about them in detail before pleading guilty to reduced charges. Pfc. Michael Burnett told the judge Roark, whom prosecutors say was helping the militia buy guns, had just left the Army and was considered "a loose end" by Aguigui, the militia's leader.

Burnett said Roark and his girlfriend were led to the woods. Peden shot York before she could get out of her car, Burnett testified, then paused to check her pulse and shot her again. Roark was forced to kneel on the ground before Salmon shot him twice in the head, Burnett said.

Roark's father, Brett Roark, yelled at Salmon from his seat in the courtroom, calling the soldier a "Piece of (expletive)." Then during Peden's turn in the courtroom later, York's stepfather bolted from his third-row seat in the courtroom gallery and rushed toward the suspect at the defense table.

"You (expletive) killed my kid!" Wesley Thomas cried out before at least four deputies and officers wrestled him to the floor and handcuffed him.

Brett Roark stood in his seat and yelled to the deputies: "Get off him!" and "Let him go!" Both men were led from the courtroom, but neither was charged for the outburst.

The Army brought its own murder charges in the case in March, but dropped them earlier this month. Civilian federal prosecutors won't say if they're building a case.

Durden, the state prosecutor, says he doesn't know how many other members belonged to the militia, which prosecutors say was called F.E.A.R. -- Forever Enduring Always Ready. Army authorities have indicated they don't believe the suspects were part of a large group.

"We have one investigation that encompasses all the allegations made against these suspects," said Chris Gray, spokesman for the Army's Criminal Investigations Command. "We're not aware of any other subjects beyond this."