A wealthy Phoenix man is shot to death while on the phone with his daughter. The entire incident was captured on surveillance video. But that's not all those cameras recorded. In fact, those other videos would raise some serious questions about the murder.

It's a picture of domestic heaven. And Donald Mellon is your typical doting daddy, a clean-cut family man his girls admire and adore.

Donald's family owns successful McDonald's franchises in their home town of Phoenix, Arizona. Donald, his wife Karen and their three kids live a nice, comfortable life.

"Unfortunately, he turned to the alcohol and he just wasn't strong enough to give up the alcohol for his family," said Karen Lawson, Donald's ex-wife. "And with raising three kids, I couldn't do it anymore."

Karen divorces Donald. The clean-cut all-American dad transforms. The newly single dad is now under the influence of more than just liquor, drowning his sorrows in the intoxicating charms of an exotic dancer named Rebekah Cheever.

"She was some young girl that was stripping, drinking, and she met an older man that had money and she needed money, he needed company," said Darcie Mellon, one of Donald's daughters.

Turns out this is no rebound romance -- it leads down the aisle, and to big trouble. Donald sets himself up in a new home with his new wild-child bride and her young son Thaddeus. Now, daddy can really cut loose.

"My first thought was 'Wow, this lady is fun,'" said Darcie Mellon.

Their friend Keetah Adair says parties with this odd couple were a blast.

"He was very charismatic, funny, one of the most amazing, giving individuals I've ever met in my life. Rebekah was young, beautiful, feisty, fun," said Keetah.

But if you ask Donald's ex, the hard-partying, ex-stripper Rebekah was too much fun.

"She showed my daughter a picture of her giving him oral sex," said Karen Lawson, Donald's ex-wife. "She was taking them to go egging houses. And the amount of alcohol in the house, I knew that that was not any situation for any child to be in."

All that alcohol isn't good for Donald either. The clean-cut family man starts to change, first on the outside, then on the inside, answering to Rebekah's nickname for him: D.J.

"The minute he met her, he turned into 'D.J.,' into something that I had no idea who he was anymore," said ex-wife Karen.

And D.J. and Rebekah are arm-in-arm, racing down a path of destruction, stocking up not only on liquor, but a terrifying arsenal of guns. Friends say they're locked and loaded in every possible way, and even their party buddies smell trouble.

"They woke up, their breakfast was a big ol' bottle of chardonnay. By lunchtime, they were drinking vodka mixed with something, doing shots, wine all night long," said Keetah. "And it seemed like they never slept or ate. It was just a recipe for disaster."

And on the hot night of July 31, 2012, that simmering tension explodes. Rebekah makes an incoherent call to 911.

By the time EMS arrives, there's no saving Donald Mellon from a single gunshot to the head. He's dead at the hospital two hours later. Responding officers find a pistol stuffed between couch seat cushions.

At the police station a woozy Rebekah tells cops she had been drinking and has no idea what happened to her husband.

"I like drank like two drinks, he drank two drinks," Rebekah tells detectives in a recorded interrogation. "I like came out of the room and then I was like 'Why are you laying on the ground, what are you doing?' And then I was like 'Oh my God,' like, there was like blood coming out of his head and, I like called 911 like right away."

Rebekah may not know, but Donald's own daughters hear the awful truth for themselves: a message from their father at the very moment Rebekah kills him.

"My sister Ashley, she was like 'He called me last night. He left me a voicemail, let's listen to it,'" said Darcie. The message had been received at 9:44 p.m. "We put the phone on speaker."

On the recording, they hear: "Hey call me. What the [----]?" "[----] it!" followed by a loud bang.

"It was like he looked up and he saw her with a gun," said Darcie. "Just to know, Wow, I heard my dad's last words."

Donald's daughters are sure that it was Rebekah sounding determined just before pulling the trigger on the recording.

"My first thought was 'This evil bitch.' I knew that she was capable of something like this," said Darcie.

A camera on the living room wall would prove Darcie correct. When investigators view security footage at the moment marked 9:44 p.m., the full story of that night suddenly emerges.

In a tape so shocking and gruesome police won't let us show it, Rebekah enters the living room while Donald's leaving that message for his daughter; she raises a gun to Donald's face, takes aim and fires. The bullet grazes Donald's skull, lodging right in Rebekah's wedding picture.

"She went and changed shirts, she went and put on a shirt that said 'Shooters World. And then she went back and shot him in the head," said Donald's ex-wife Karen Lawson.

What the tape reportedly shows after that fatal gunshot is just as horrifying. Cops say while blood pours from Donald's head, Rebekah sits down on the couch right next to her dying spouse for 23 full minutes and casually smokes a cigarette.

Donald's daughter believes those 23 minutes were the difference between life and death for her dad. By the time Rebekah finally makes that rambling call for help, it's too late to save him.

The video proves it. This is an open-and-shut case of cold-blooded murder. Or is it?

Keetah and Marcus Adair lived with Donald and Rebekah Mellon for a year, witnessing firsthand the out-of-control drunken parties, and much more.

"It would be so calm and chill and then somebody had too much to drink and Rebekah could be nagging and annoying and not know when to stop," said Keetah.

"He would get upset. There were times where she would instigate, there were times he would hit her," said Marcus.

The boozing is non-stop and the violence is so frequent that Keetah and Marcus finally had enough.

"It got to a point where they were just both so bad that we just, we couldn't stay anymore," said Keetah.

"Something bad was about to happen and we didn't want to witness it."

Phoenix Police witness it -- a lot. In just one year prior to the murder, cops are called to the home an alarming 21 times for incidents including welfare checks and reports of domestic violence and assault.

On a visit dated March 13, an officer notes "swelling and redness" around both of Rebekah's eyes, and a chilling exchange with the battered woman, writing: "She was mouthing the words 'Help me.'"

Police say when Rebekah heard Donald was being arrested, she said in the police report: "You have no idea what you guys just did to me. You have killed me. He's just gonna kill me."

"She became extremely terrified because she felt like D.J. was going to be thrown in such a state of anger that he would kill her in the future," said private criminal-defense investigator Justin Yentes.

Donald tells cops "they're all lies." But were they?

Jennifer Willmott is Rebekah's attorney, well-known for defending Jodi Arias, a notorious murderer convicted of killing her allegedly violent lover. Willmott says Rebekah's horrific abuse is all there, caught on tape.

"There's surveillance in almost all of the rooms of the house and outside," said Willmott. "When we actually looked through hours and hours of tape, we actually found quite a few more incidents."

Terrifying incidents including Rebekah on the receiving end of a ferocious roundhouse slap; being dragged to the ground in front of her son Thaddeus; in the kitchen, a punch to the back of her head followed by Donald pouring water over her head.

And the fights aren't just behind closed doors. The backyard camera catches a furious Donald chasing down a family pet, then going after other Rebekah.

"Rebekah comes outside and she walks towards Mr. Mellon. He walks towards her, and then he just grabs her by the shirt, and he is dragging her by her feet, and then he pulls her up by her shirt and then ultimately tosses her in the pool," said Willmott. "He comes inside and he locks the door.

"That's just in one week's time and that just happens to be caught on tape, and so, who knows what was going on before that, and how often it was?"

Then there are the guns: a locker full of pistols, shotguns and assault weapons, adding an alarming level of danger to the couple's combustible "War of the Roses."

"He would pull guns on her. He pretended to play 'Russian roulette' one time with her," said Jennifer Willmott.

According to Willmott, Rebekah wrote in her journal there was one final threat that sent her over the edge.

"What Rebekah remembers is that he had been talking about how he was going to hire somebody to break into the house and make it look like a burglary, and she was going to get killed in the process -- 'All I need to do is make the call,'" said Willmott.

But Donald's family says the defense has it backwards: Donald's only threat was to leave Rebekah, that he feared retribution from his violent bride.

"You know why there were surveillance cameras? Because he was afraid she's going to kill him," said ex-wife Karen Lawson. "He knew it somewhere in his head, she was going to hurt him."

Karen says what the clips only show Donald's violent reaction and not Rebekah terrorizing Donald.

"I know she antagonized him, I know she would do things to purposely hurt him and then get in his face and say 'This is what I did. Did it hurt you and what are you gonna do about it?'" said Darcie Mellon.

"I think people hear her version and they think, 'Oh my God, well good for her, good for her for getting him.' And it infuriates me. It infuriates me because it's not true. You're literally hearing one side of the story, which is being told by a pathological liar," said Karen Lawson. "He never, ever, ever raised a hand to me, much less his voice."

Rebekah is charged with first-degree murder and held on a $1 million bail. Her defense claims she was a battered woman who shot her husband in self-defense. Disturbing surveillance videos could sway a jury, but she's gambling with her life again by going to trial.

"Had Rebekah gone to trial and lost, she would be facing the rest of her life in prison," said Jennifer Willmott, Rebekah's defense attorney. "She would never, ever get out. She didn't want to risk it."

So before a jury gets to decide on her guilt or innocence, Rebecca takes a plea deal to second-degree murder. Her attorney Jennifer Willmott still argues Rebekah never intended to kill Donald.

"Why would a woman who had been continually abused for years fire one shot that just grazes his head if she was truly intending to kill him? What would be the point of that? It would be much more likely for her to fire numerous shots to make sure she got him, and then call 911 once she knew he was dead," said Willmott.

At her sentencing, Rebekah admits she was drinking that terrible night, and maintains she doesn't remember the crucial 23 minutes after the shooting -- the 23 minutes that could have been difference between life and death for Donald Mellon when he lay bleeding to death while she sat and calmly smoked a cigarette.

But it's evidence the Maricopa County judge can't ignore. She's seen the video.

Despite her claims of abuse, the plea deal still puts Rebekah Mellon behind bars for 20 years for the murder of Donald Mellon.

With more than 15 years still left in her sentence, Rebekah Mellon agreed to talk about that tragic night for the first time on national television, in a phone interview from behind bars with Crime Watch Daily's Ana Garcia.

When she looks at that videotape of her shooting her husband, what does she think?

"I think it looks horrible and it just sucks 'cause it's like I don't remember it happening," Rebekah says.

But she has the ability and the concentration to sit down and have a cigarette, and based on the video it appeared like she was watching.

"Yeah, I didn't remember even smoking or any of that," Rebekah says. "And I didn't come back into focus until I saw him on the couch."

Anyone who endured what we saw her endure in those videos, how could she not want to hurt him back for the way he treated you?

"It's just not the type of person I am. I've never been like that, and I've never done anything to hurt anybody, and you know, I had like never even been in a fight or anything like that. I'm not that type of person," Rebekah tells Crime Watch Daily.

Then she reminds Ana of her shocking claim, that on the same night she pulled the trigger, Donald was planning to have her killed.

"When the gunshot went off, everything went blurry and it, I didn't mean for it to go off, you know -- I just was trying to plead my case before he made, you know, this phone call that was supposed to be the hit-man coming for me," says Rebekah.

For Donald's heartbroken daughter, the memory loss is all just another excuse from Rebekah.

"That just screams 'bull crap' to me, that's just a dumb story. Now that I hear that I'm just like, that's a lot of crap, you know," said Darcie Mellon, Donald's daughter.

"He wasn't a bad guy and he wasn't this man that is being put out there, that's not who he was in any way, shape or form," said Donald's ex-wife Karen Lawson. "Rebekah is really good about portraying herself as this meek little battered woman and that's -- she's far from that."

And Darcie believes justice would have been life in prison for the life Rebekah stole from her.

Do you think Rebekah deserved more than or less than her 20-year prison sentence for what she did? Sound off in the comments section below.