UPDATE May 23, 2018:

Judge Robert McBurney sentenced Tex McIver to life in prison with the possibility of parole on May 23, 2018.

May 2, 2018

Mistake? Or murder?

It's the question investigators have been asking since the day Claud "Tex" McIver was found holding the smoking gun that killed his wife.

But now, as of just days ago, that question may finally be answered. Prosecutors are taking Tex to court, revealing all new evidence, shocking surprise witnesses, and even newly released video of Tex with the victim just moments before she died.

Did Tex McIver kill his wife in cold blood?

They were the last couple you'd expect to find at the center of a murder investigation. He was a prominent lawyer and vice chair of the Georgia State Elections Board, and she was a dynamic, self-made business executive known for her extreme generosity. Together they owned a massive ranch in Putnam County, Georgia, along with an extravagant weekend home in the Atlanta suburb of Buckhead.

But on a late night in September 2016, these two pillars of the community would become known for something much more tragic.

It began with a leisurely day of golfing at the ultra-exclusive Reynolds Golf Club on Lake Oconee, and some wine-tasting. Tex tells police that after that, Diane's longtime friend Dani Jo Carter offered to drive everyone home since she wasn't drinking.

Then, a detour. After falling asleep in the backseat, Tex says he wakes up to find Dani Jo driving through a sketchy neighborhood. Nervous, he says he asks his wife to hand him a small .38-caliber revolver from the center console.

"And Tex fell back to sleep. McIver's attorney then says that Tex woke up to the sound of a gunshot, and realized that the gun went off while Tex was holding it," said WGCL-TV CBS46 Reporter Natalie Rubino.

Diane slumps, bleeding from the gunshot wound. Terrified and panicked, Tex tells Dani Jo to get to a hospital emergency room. But Tex directs her to Emory Hospital five miles away, oddly bypassing three closer hospitals along the way.

"They took her to that hospital because Tex believes it's the best hospital in the Southeast," said Rubino. "They also said that they didn't call 911 because they didn't want to waste time."

In newly released surveillance video, you can see Tex waving Dani Jo to the front of the E.R., then helping his dying wife into a wheelchair. Tragically, nothing can be done. Diane McIver dies in the E.R. Tex tells investigators just before Diane passed, she told doctors her husband didn't mean to shoot her.

But in the days after that, investigators started to wonder just how accidental was the shooting after all.

Crime Watch Daily wanted to know if Tex's gun could've really just "gone off" as he claimed, so we brought in our own expert to test the theory.

"Revolvers are very reliable mechanical instruments," said gun expert Ken Baye. "It's designed to fire only when you pull the trigger. You have to really mean to pull the trigger. It doesn't just accidentally go off."

And there was something else. Tex told police the gun fired after they hit a bump in the road. But Dani Jo Carter, the woman who was driving the car, says they were actually stopped at a red light.

And just weeks after the shooting, our Atlanta affiliate CBS46 uncovered a stunning detail about the couple's finances: Tex owed Diane money. Lots of it. According to the agreement, in December 2011, Tex borrowed $350,000 from his fabulously wealthy wife. It was supposed to be paid back with interest by December 2014. Tex failed to do that. So Diane gave her husband an extension until December 2017.

Tex put a treasure trove of Diane's luxury clothes and jewelry up for auction, more than 2,000 items, just two months after her death. His lawyers say the auction provided the cash to pay the people Diane named in her will.

But would that be proven to a jury?

After months of investigation, a grand jury indicts Tex McIver on seven felony counts, including influencing witnesses, assault with a deadly weapon and murder.

And as he faces prosecutors in court, they're saying Diane's death was all part of a diabolical plan.

Now it's up to a jury. Was Diane's death an accident? Or a murder?

For seven excruciating weeks of testimony, Diane's husband, 72-year-old Claud "Tex" McIver, sits on pins and needles in an Atlanta courtroom, occasionally brought to tears as prosecutors lay out their evidence of what they say is Tex's ruthless motive for killing Diane: money.

But Tex's potential windfall wasn't a sure thing. The district attorney alleges Diane planned to foreclose on the $350,000 loan she made to Tex. After that, she'd turn around and gift Tex's extravagant ranch to Diane's godson, 7-year-old Austin Schwall.

Authorities say that's something Tex wasn't about to let happen.

But as prosecutors lay out more evidence of premeditated murder, they've got a couple of tricks up their sleeves.

First on the stand, star witness Dani Jo Carter. She's been tightlipped during the investigation. But now, Dani Jo opens up about that terrible day with a blow-by-blow recreation of that final car ride.

"I heard a big 'boom' and I didn't know what it was, I thought there was an explosion somewhere, or somebody behind us was getting ready to hit us or something had happened behind us," Carter testified. "I did not realize that it was a gunshot right away."

Even though she was just inches away from the gunfire, she didn't really know Diane had been shot.

"This was all happening in seconds and I saw a puff of smoke and I could see his hand, his hands, and I could see the top of the gun, I could see part of the gun, his hands and some of the bag. And his hand was moving like this. I thought it was a joke, and then I realized it wasn't."

Carter says she quickly knew those harrowing minutes after Tex shot Diane were a matter of life and death. As she raced to Emory Hospital, she could hear Diane's life quickly slipping away in the front seat. Then she shocked the court, testifying Tex actually told her to slow down while directing her to the emergency room.

"He told me I needed to be careful. That there might be people out there walking with baby carriages," said Carter.

At trial, surveillance video shows Tex waving Dani Jo to the front of the E.R., then helping his wife Diane into a wheelchair. His defense team claims that just before Diane died, she told doctors it was all an accident. But according to Carter, it was Tex's words at the hospital that night that had the biggest impact -- specifically when he pulled her aside, just out of earshot of police officers, and said this:

"'I don't trust these guys. Dani Jo, I hate to see you get wrapped up in this. I've seen how these things can go down. You just need to say you came down here as a friend of the family.' I said 'Tex, I just drove you into the emergency room.' He looked at me and he says 'Well, they don't know that.' I said 'I can't lie.'"

But what happens next really raises red flags. Tex holes up in the couple's high-rise condominium, a mystery woman by his side. For years, Annie Anderson was Tex and Diane's fitness coach and massage therapist. And authorities are asking what was she doing staying at Tex's condo just one day after Diane died on an operating room table.

The defense cries foul and puts Anderson on the stand to set the record straight. She says Tex's state of mind was guilt-ridden and distraught, and that sex was the furthest thing from his mind, or hers.

For days, the jury huddles over the case, even sitting in Tex and Diane's SUV to reenact the shooting. Was this an accident? Or cold, calculated murder?

When jurors come back with their decision, it's a shocker.

The 75-year-old former attorney has been in custody for months. He was not allowed out to attend his mother's funeral.

"From the very beginning the prosecution was criticized for having a weak case," said WGCL-TV Reporter Natalie Rubino.

But as trial watchers wait breathlessly for the jury's decision, the moment of truth is put on hold. Jurors were deadlocked on some of the charges over wording, according to one juror.

It was looking like the seven-week case was about to be declared a mistrial. But the judge wasn't having it. He clarifies the charge and tells the jury to keep deliberating.

Then, just two hours later, the court reconvenes. A hush falls over the courtroom as the verdicts on five separate charges are read. On count one of murder, Tex McIver is found not guilty. But there are four more to go -- and suddenly any chance of Tex walking free completely disappears.

"On Count 2, we find the defendant guilty of felony murder."

The rest of the verdicts are no better for Tex McIver. Aggravated assault; possession of firearm while committing a felony; influencing a witness: all guilty.

Juror Lakeisha Boyd says it was a simple matter to find Tex responsible for Diane's death.

"He had knowledge of guns. So therefore that was reckless for you to ask for a gun then fall back to sleep and your hand was on the trigger," said Boyd. "So that's were the aggravated assault came."

"Under Georgia law, if a person is found guilty of aggravated assault and the victim dies as a result, that person must be convicted of felony murder," said reporter Natalie Rubino. "In Georgia, felony murder comes with a mandatory life sentence."

"Guilty" is the last word Tex McIver hears as a free man. Immediately after the verdict is read, Tex is stripped of his belt, slapped in cuffs and perp-walked to jail.

Sentencing is scheduled for the end of May, when McIver's attorneys will argue he should be given the possibility of parole.

But it may not matter. Tex McIver will almost certainly die behind bars.

"He won't be eligible for parole until he's served 30 years in prison," said Rubino. "Tex is approaching his mid-70s. So in many ways this is a death sentence for him."

Because Tex McIver was convicted of felony murder, the district attorney says McIver will not have access to Diane's $7 million estate.