Affair leads to shocking Ga. double murder

Robin Heidt tells "48 Hours": "I had a secret...and once it was exposed, all hell broke loose"

Nine months after the Heidt family murders came bombshell news: Craig Heidt was about to marry Robin, his dead brother's wife.

"You were gonna get married to Craig. Take the kids. Get out of Effingham," Susan Spencer commented to Robin Heidt.

"That was the plan, the future plans," she replied.

The community had some questions.

Sheriff Jimmie McDuffie said he was asked, "'Why aren't y'all puttin' him in jail?' I had one lady even call me and tell me I need to go see the governor and make the governor make GBI make an arrest."

Finally, in May 2009, the Georgia Bureau of Investigation made its move, arresting Craig Heidt for the murder of his brother.

"Did that shake your faith in him?" Susan Spencer asked Robin Heidt.

"No," she said. "I was convinced he was innocent and that he was being treated unfairly."

Craig also was charged with killing his father, Philip, and attempting to kill his mother, Linda. But Linda is convinced that her oldest son is innocent, denying suspicions that she secretly knows otherwise.

"As a mother, I could not sacrifice the son that was killed and my husband that was killed to protect another son if I really thought that that son did that," Linda told Spencer.

Brother Chris is just as sure. "It took a coward to walk in at three in the morning into a dark home and do what they did to our family," he said. "...that's not Craig...Craig's not a murderer..."

But prosecutors think a jury will decide that's exactly what he is. On Dec. 1, 2010, the murder trial of Craig Heidt begins in the Effingham County Courthouse.

"When you sit down and dispassionately look at the evidence, it couldn't be anybody but him," said District Attorney Michael Muldrew.

Muldrew argues that the shooting made perfect sense if you thought about it as Craig did.

"'The only way I'm gonna have Robin Heidt and have peace is Momma, Daddy, and Carey have to be eliminated from the equation.' He wanted the big house. He wanted the kids that adored him. He wanted to drive around in the nice truck and the life of leisure of a southern gentleman so to speak," said the district attorney.

Craig Heidt's lawyer, Dow Bonds, says the public perception that Craig somehow was trying to "become" his brother is completely distorted.

"The first thing I noticed about Craig when I first met him was what a genuine person he was and what a gentleman he was," Bonds told Spencer.

In his opening statement, Bonds told the court, "What shocked me was just the clear lack of physical evidence linking him to the murders. There's no DNA. There was no fingerprints. There were no eyewitnesses. There are no confessions..."

Perhaps the prosecution's strongest physical evidence are the bruises on Craig's arms.

To the medical examiner, the explanation is obvious.

"I think they are very consistent with someone who has fired a shotgun," testified Dr. James Downs.

But Craig sticks to his story that he got the bruises in that bizarre bathroom tumble onto the toilet, an event he recreated with himself in the starring role.

The video was made before Craig Heidt had a lawyer.

"If I had been representing him at that time, I would have said...'You know, don't. A reenactment is not a good idea...' But if you look at what Craig was thinking at the time he did that, he was trying to assist them in their investigation...he was cooperating with them," said Bonds.

Prosecutor Muldrew shows the video in court, telling the jury Craig could not possibly have gotten those bruises falling on a toilet.

"To have happened like that is truly impossible," Muldrew said. "Most people that saw it literally laughed at this reenactment he did. ...it was silly."

Brother Chris Heidt was not laughing then or now.

"The position of the bruises on Craig's body were actually impossible to make from a shotgun," said Chris.

Chris says a shotgun would have to be held at a ridiculous angle to get those bruises and Craig knew better...but in the heat of murder? Firearms expert Ed Myrick thinks a shotgun easily could slip.

"And if it does, it's gonna get more on my arm, which is gonna leave more bruising and it's gonna hurt me more," he explained.

"So in an ideal world, if you were shooting, the bruising would be here?" Spencer asked, pointing to the middle of her upper arm.

"Correct," said Myrick.

"But if you're maneuvering around something or in a hurry or whatever, you can also suffer bruises more toward the outside of your arm," noted Spencer.

"Exactly," Myrick said. "If this gun slips at all, it will fall toward your arm and it will definitely tear you alive."

Asked what he believes Craig Heidt did that night, Muldrew told Spencer, "It's not really a matter of what I believe he did. ...It's what I know he did."

For Muldrew, the key to the case against Craig is, quite literally, a key.

"He knew somethin' that very few people knew and that is the location and presence of another key...an outside key...which people commonly have," he said.

The prosecutor thinks Craig smashed the pane of glass to fake a burglary when, in reality, he simply opened the door with that spare key.

"He knew where that key would've been located. He took that key, opened the door, went in," said Muldrew.

And in his haste, Muldrew continues, he forgot to take the key out of the door, where the cops later found it.

Once inside, according to this scenario, Craig methodically went room to room... shooting his brother, his father and his mother all for the love of Robin.

"Do you think their affair had anything whatsoever to do with the murders?" Spencer asked Chris Heidt.

"She's definitely responsible for Carey being in the home that night, 100 percent. If Carey was livin' happily at his house, he'd have never been at my mother and father's that night," he replied.

His mother and brother stand by him, but if Craig Heidt thinks his former lover and sister-in-law is still with him, he's about to get a nasty shock.

"When I looked at him, I just felt disgust, disgust at the affair, disgust at just him period," said Robin.