Produced by Marcelena Spencer
[This story first aired on Feb. 16, 2013. It was updated on Sept. 21.]
Sergeant Brent Burke earned his stripes at Fort Campbell, Kentucky -- home base for his division, the legendary 101st Airborne. Once under the command of former General David Petraeus, the soldiers of the 101st have seen more action than most soldiers in the U.S. Army.
It is also where Sgt. Burke will learn if he will continue to serve in the Army, or if he will serve out his life in prison, because military prosecutors in the Army's Judge Advocate General's Corps, known as JAG, will court martial Sgt. Brent Burke for double homicide.
"I would say that the tough part of any case like this is the fact that it was four years old ... and it was mostly circumstantial evidence and when you put all that together it certainly makes for a difficult case," JAG prosecutor Lt. Col Matthew Calarco told "48 Hours" correspondent Richard Schlesinger.
Lieutenant Colonel Matt Calarco's mission, after four civilian trials failed to get a verdict, is to finally prove Sgt. Burke shot and killed his wife, Tracy, and her ex-husband's mother, Karen Comer, on Sept. 11, 2007.
"We knew that somebody had gone to Karen and Kurt Comer's home ... and gone to their back door, shot Karen Comer, gone into the house, shot Tracy Burke - left three children there ... and left the house," said Lt. Col. Calarco.
Matthew Pete, Tracy's son from a previous marriage, witnessed a horror when he was only 9 that no child - and no adult - should ever have to see. He was there when his mother and grandmother were shot dead.
" ... I hear a couple of gunshots going through and some glass breaking and my grandma screaming that she's dying ... I hear a couple more shots. And then I'm down on the couch ... shocked, never really thought this would be happening," Matthew told Schlesinger.
His younger brother, Eion, who was 4, and his sister, Raegan, who was 2, were all in the house when the murders were committed:
911 Dispatcher: Where are they at right now?
Matthew Pete: They're dead in my house. There's blood spattered everywhere.
911 Dispatcher: Do you know who done this?
Matthew Pete: No.
When, he said he didn't know who the gunman was, but was certain he was wearing a camouflage jacket similar to one Sgt. Burke might wear. Kentucky State Police investigator Mark Gillingham interviewed Matthew days after the murders.
"... He described -- the camouflage jacket as being what we call the woodland pattern," Gillingham explained. "And he said he remembered one being in his -- stepdad's closet ..."
Investigators never found a jacket like that in Burke's barracks or his van. But Gillingham also interviewed Matthew's brother, Eion, who said his father, Sgt. Burke, was the killer.
"And how able was Eion to communicate with you?" Schlesinger asked.
"... he was very easy to communicate," Gillingham replied.
"And what did he say?"
"'You wanna talk to me about my daddy shooting my mommy,'" said Gillingham.
Tracy and her husband, Sgt. Burke, who was a military policeman, were divorcing. Tracy and her three children were staying with Karen Comer in Rineyville, Ky. Sergeant Burke was living at Fort Campbell, 140 miles away.
"... he got off of work at approximately 10:30 in the evening," JAG prosecutor Major Sondra Smith explained. "And from testimony that his roommate gave us, he returned to the barracks at approximately 11:30."
Sergeant Burke then leaves and he is not seen until about 6:30 the following morning when his roommate returns from PT ... physical training. So, that whole period of time is unaccounted for."
"And that's how many hours?" Schlesinger asked.
"It was 11:30 till 6:30, so seven hours," Maj. Smith replied.
"So what do you believe he did in those seven hours?"
"Well, we believe he rode to Rineyville and he killed Karen and Tracy Burke ..." she said.
Former JAG Captain Nathan Brown was one of Sgt. Burke's military defense attorneys.
"From the moment I started reading anything about this case, it's like, why is the Army doing this?" Brown told Schlesinger. "... the fact that it's a two-and-a-half hour drive from Fort Campbell to Rineyville and back ... I don't see how someone could drive that, do whatever they needed to do to get into the home, do what they did, exit the home, dispose of every single shred of evidence, drive another two-and-a-half hours back, and be sound asleep in their bed when your roommate comes in the morning."
A shattered glass door and shell casings were discovered at the scene.
Investigators have never found any blood, DNA, or a murder weapon linking Sgt. Burke to the crime.
In an interview with reporter Eric King for CBS affiliate WLKY, :
"I'm an innocent man, and I'm a father and I'm a soldier and I need to go home to my family," Sgt. Burke said.
All the families involved in this case are military families and proud of the tradition. Master Sergeant Michelle Kerstetter is an Air Force reservist, and Karen Comer's daughter.
"In my head I just like to think that she was in the wrong place, wrong time. I just knew that Brent killed my mom," Kerstetter said
Sergeant Burke's father, Stan, is a highly decorated Vietnam War veteran. He earned a Silver Star and a Purple Heart.
"How certain are you that your son is innocent?" Schlesinger asked.
"I've asked Brent actually more than once. I said, 'Did you have anything to do with this?' and he says, 'No.' And I said, 'Fine.'
That's all I needed to hear," Stan Burke replied.
But Tracy's father, David Wilburn, who is retired from Army Artillery, says Burke is the only suspect because of what his daughter said to him after Burke's last visit with the kids.
"'Dad, she says, 'I'm uneasy. He's actin' very strange," Wilburn told Schlesinger.
"Did she describe how?"
"... the way he acted when he come in the house wantin' to know where everybody was sleeping, who slept in what room ..." he replied.
"Did you think that was odd?" Schlesinger asked.
"Yeah, I did," Wilburn replied. "... and that's when I told her, I said, 'you need to come here. I'll come get you right now.' She said, 'Dad, I got it.'"
That was Saturday. By Tuesday Tracy was dead.
You'd be forgiven for thinking this is an open-and-shut case. But then almost everything that could go wrong did go wrong. And it began to look like it would take an Army to drive this case to a conclusion.