JOHN YANG: A new chapter is unfolding in a story of power, privilege, and violence.

Last year Alex Murdaugh was convicted of murdering his wife and son in South Carolina.

The case gripped many across the country.

And now the state Supreme Court has agreed to hear his appeal.

A new book chronicles not only the story of the murders and the trial, but a family that for a century used violence to gain power.

Lisa Desjardins has more, beginning with a reminder of Murdoch's tangled history.

QUESTION: Alex, did you kill your wife and son?

LISA DESJARDINS: In a small courthouse with millions of people watching, last March, a jury convicted formerly powerful attorney Alex Murdaugh of the unthinkable, shooting and killing his wife and younger son, Paul.

Prosecutors say it was a desperate attempt by Murdoch to distract as years of stealing millions from his clients was coming to light.

Lead prosecutor Creighton Waters: CREIGHTON WATERS, Chief Prosecutor: It doesn't matter who your family is.

It doesn't matter how much money you have or people think you have.

It doesn't matter what you think, how prominent you are.

If you do wrong, if you break the law, if you murder, then justice will be done in South Carolina.

LISA DESJARDINS: The trial reads the specter of other deaths around Murdaugh and his immediate family,the fatal head injury attributed to a fall of their housekeeper five years earlier, the death of 19-year-old Mallory Beach after witnesses say Paul Murdaugh drunkenly crashed his boat, and the death of a teenage classmate of Murdaugh's older son ruled a hit-and-run, but which police later investigated as a homicide.

The Murdaughs publicly denied responsibility for any of that.

On the stand in his wife and son's murder case, Alex had to admit he lied to police after cell phone video proved he was at the scene of the crime minutes before the death.

In a separate case, Murdaugh admitted guilt to financial crimes, stealing life-changing legal settlement money from impoverished clients.

He blamed drug addiction.

The isolated Murdaugh estate, where the family murders, happened has been sold.

But what happened there is still making headlines.

A new book chronicles this saga and goes further, looking at not just Alex Murdaugh, but 100 years of eye-popping privilege and violence connected with his father, grandfather and great-grandfather.

The book is "The Devil at His Elbow: Alex Murdaugh and the Fall of a Southern Dynasty" by Wall Street Journal reporter Valerie Bauerlein.

She joins me now.

Congratulations.

You're an instant bestseller.

VALERIE BAUERLEIN, Author, "The Devil at His Elbow: Alex Murdaugh and the Fall of a Southern Dynasty": Thank you.

LISA DESJARDINS: There are a lot of true crime stories these days.

What about this one made you want to write a book?

VALERIE BAUERLEIN: I was captivated by the same thing that the country was captivated by, right?

I mean, this story had everything.

It had all seven of the deadly sins.

I went and looked them up, and I was like, yes, it does.

It had mystery.

Who killed Maggie and Paul?

And then once we found out that Alex was charged, why and how?

How could a man kill his wife and son?

And I think, as much as anything, for me, I grew up in the South.

I have covered the South my entire career.

It's really the only place in the country that just evokes an image in your mind.

And once I started digging in on the history, I was like, wow, you can tell the story of the rural South through the lens of this family, in addition to every other thing it shows us about American life and American tragedy.

LISA DESJARDINS: I want to have you read a passage about Alex Murdaugh in chapter four.

Can you read how you describe him there?

VALERIE BAUERLEIN: "He was the kind of guy who could, in the course of a day, score some pills, cheat on his long-suffering wife, fix three different court cases in three different counties, head to Hampton's little league fields to coach one of his son's teams, and then host the after-party for players' families."

LISA DESJARDINS: Now, this is the same man who spent years embezzling millions, committing massive fraud, in fact.

And he lied to the police on the night of his wife and son's murders.

Yet he took the defense stand.

In the end, how did you come to understand this man?

And is he someone who understands the truth himself?

VALERIE BAUERLEIN: I think he gave us two days of who he was when he took the stand in his homicide case.

But I think he also, in addition, talked an additional 45 minutes uninterrupted back in November in Beaufort when he was finally sentenced for stealing millions of dollars.

I watched him.

I can remember putting my pencil down and just leaning forward and being like, he doesn't know himself.

He's a walking mirage, and nobody really knew him.

LISA DESJARDINS: Do you think he's someone who believes he's above the law?

VALERIE BAUERLEIN: There's no question in my mind that Alex Murdaugh thinks he's above the law.

And I think that is an inherited belief.

The story of the book is really the story of five generations, essentially, of Murdaughs.

They realized that, to be above the law, you had to become the law.

And they were the law.

Alec's father, his grandfather, and his great-grandfather all held the office of solicitor, which is district attorney, but it's so much more than that in a rural area.

They were the lead lawman for a five-county area for a century, and in a place where there would be maybe a sheriff, a deputy sheriff, and a jailer.

But that was it.

The Murdaughs were the finder of fact.

They were the detectives.

They were the law.

LISA DESJARDINS: That's incredible power.

And going through that, his great-grandfather - - through your incredible research over years, great-grandfather committed, an insurance fraud scheme that led to the family's wealth.

Grandfather ran a bootlegging operation.

VALERIE BAUERLEIN: The largest in the South.

LISA DESJARDINS: And got away with it, it looks like, with jury tampering, while he was a prosecutor, by the way.

His own father, there's evidence that he covered up a violent boat crash.

I want to ask you the theme of this book.

What did you learn about this family and power and deceit, how they tell lies and get away with it?

VALERIE BAUERLEIN: What I learned about this family is that they had perfected the art of making a lie look like a truth.

And for a long time, that was easy enough to do when you are the law.

There was no electronic records.

There were not cameras falling us at all times and if you say, no, that never happened -- or in the case of his grandfather, who was accused of running the largest bootlegging ring in the South by the DOJ, I mean, by the Department of Justice, he was like, I never took a cash bribe out in the hallway of the college and county courthouse, the one where we were every day in court.

So they just had mastered the art of making problems go away.

And they could because of generational privilege.

LISA DESJARDINS: And generational wealth that they passed on through... VALERIE BAUERLEIN: Generational wealth that was -- it was a dynasty forged in fraud.

I think the evidence completely supports that.

LISA DESJARDINS: What do you think this tells you about this particular place in the South?

VALERIE BAUERLEIN: You know, it really is so isolated and so poor.

The median family income is half the national average.

People -- there's no net migration, right?

Nobody moves in.

Nobody moves out.

It's been 20,000 people for 100 years.

So it really has been immune to change partly because of the iron fist of this family.

One of the perverse legacies of the Murdaughs was, they were the solicitors, right, but they also ran this very powerful civil law firm.

And because they knew everybody, guess what?

The jury awards in civil cases were enormous.

And that had the perverse impact of scaring businesses away.

So, all that is to say, the economy is not vibrant at all.

There are many people that I have come to really care about in Hampton, and they have been left with a hard situation as a result.

LISA DESJARDINS: This story is something obviously that a lot of people paid attention to for the details.

But I also want to talk about Murdaugh's victims.

You spent time talking with them, some of the poorest of the poor, who he stole from.

What is the takeaway for them?

VALERIE BAUERLEIN: You know, I really thank you for saying that.

I really did try to let you know a lot more about the poorest and most vulnerable people that he stole from, motherless girls, a quadriplegic deaf teenager.

He stole their future.

He stole their money, but he stole their chance at a life.

And what I wanted to show was, there's a kind of moral and emotional violence to that type of crime.

And I think, over the course of years, that violence inured him to hurting other people.

So it was not in my mind as far a leap to kill his wife and son, to cover up, as the evidence shows, to cover up, his many years of thieving.

LISA DESJARDINS: It comes back to that circle of power and deceit.

VALERIE BAUERLEIN: It really does.

LISA DESJARDINS: He is appealing, trying to appeal still.

VALERIE BAUERLEIN: Oh, he's appealing multiple things, isn't he?

LISA DESJARDINS: Do you think this case will ever end?

VALERIE BAUERLEIN: We have a first ending.

A jury of his peers in the place where he grew up found him guilty of killing his wife and son.

And then, later, he played guilty in state court to all the thefts.

So, essentially, he played guilty to the motive.

He pled guilty to the predicate crimes that the state said drove him to kill them.

No matter what happens in the future, we have an ending.

And we also know he will spend the rest of his life in prison.

LISA DESJARDINS: No one knows this case better.

Valerie Bauerlein, a gripping and meaningful book.

Thank you.

VALERIE BAUERLEIN: Thank you so much for having me.