Before imposing the sentence of life in prison, Judge Clifton Newman said, “This has been perhaps one of the most troubling cases, not just for me as a judge, for the state, for the defense team, but for all of the citizens in this community, all citizens in this state.”

“A person from a respected family who has controlled justice in this community for over a century. A person whose grandfather's portrait hanging at the back of the courthouse that I had to have ordered removed in order to ensure that a fair trial was held by both the state and the defense," he said.

To the convicted attorney, Newman said, “As a member of the legal community and a well-known member of the legal community, you've practiced law before me, and we've seen each other at various occasions throughout the years. And that was especially heartbreaking for me to see you go in the media from being a grieving father who lost a wife and a son to being the person indicted and convicted of killing them.”

“I know you have to see Paul and Maggie during the night when you are attempting to go to sleep,” the judge said. “I'm sure they come and visit you.”

"This case qualifies under our death penalty statute," the judge said. "I don't question at all the decision of the state not to pursue the death penalty. But as I sit here in this courtroom and look around the many portraits of judges and other court officials, and reflect on the fact that over the past century, your family, including you, have been prosecuting people here in this courtroom, and many have received the death penalty, probably for lesser conduct. … The question is, when will it end? When will it end? And it's ended already for the jury, because they've concluded that you continue to lie and lied throughout your testimony."

Alex Murdaugh was sentenced Friday to life in prison after being convicted of murdering his wife and their youngest son.

The life sentences for each murder will run consecutively.

Before the judge imposed the sentence, Murdaugh said, “I’ll tell you again. I respect this court. But I am innocent, and I would never under any circumstances hurt my wife, Maggie, and I would never under any circumstances hurt my son, Paul."

Judge Clifton Newman responded, "It might not have been you. It might have been the monster you become when you take 15, 20, 30, 40, 50, 60 opioid pills. Maybe you become another person. I've seen that before."

The judge said, "The person standing before me was not the person who committed the crime, though it's the same individual."

Before the sentence was announced, prosecutor Creighton Waters asked the judge to impose a maximum of consecutive life sentences.

Waters called Alex Murdaugh “a cunning manipulator, a man who placed himself above all others, including his family, a man who violated the trust of so many, including his friends, his family, his partners, his profession. But most of all, Maggie and Paul.”

“Both of them, like everyone else, was unaware of who he really was,” he said.

“I've looked at his eyes. And he liked to stare me down as he would walk by me during this trial. And I could see the real Alex Murdaugh when he looked at me,” Waters said. “The depravity, the callousness, the selfishness of these crimes are stunning. The lack of remorse and the effortless way in which he lies, including here sitting right over there, in this witness stand. Your honor, a man like that, a man like this man, should never be allowed to be among free, law-abiding citizens again.”

Alex Murdaugh gave a brief statement to the judge before sentencing, saying, “I’m innocent. I would never hurt my wife, Maggie, and I would never hurt my son, Paw-Paw.”

Lead prosecutor Creighton Waters said he believes Alex Murdaugh's lie about being at the scene of the crime just minutes before his wife and son were murdered was part of what made such a "compelling" case against him.

"It's not just being a liar. In this case, it was him being a liar about being at the scene with the victims just minutes before their cellphones went silent forever," Waters told ABC News' George Stephanopoulos in an interview Friday on "Good Morning America."

"I made the argument to the jury and the team did -- this was obviously a team effort -- that, you know, what kind of reasonable father or husband would lie to law enforcement about such a crucial fact in that moment, and only one who really knew what had happened?" he said. "When you lie about being at the scene with the victims just minutes before the crime happened, that's pretty compelling evidence."

Waters said he thinks the cellphone video placing Murdaugh at the scene minutes before the crime "absolutely" made a difference in guilty verdict.

"That was something that the defendant could never account for and I think, though, he was still hoping that that evidence wouldn't be as strong as it was," Waters noted. "He initially claimed -- because there was one young man who thought he heard him on the phone and he said, well, he's got to be mistaken. I think he thought he could get around that."

"But as we continued to put up family and friends, people who were very close to him, none of whom knew who he really was, it became very compelling," Waters said. "And I think that’s what motivated him to try to take the stand and see if he could give one last closing argument to these jurors."

The lead prosecutor said he was not surprised when Murdaugh decided to testify.

"I thought that he would do it all along," he added. "In this community, he's been able to talk his way out of accountability his entire life and people like that are convinced in their own ability to do so."

When cross-examining Murdaugh, the prosecution team's strategy was to "establish who he was," according to Waters.

"I thought it was very interesting that he would not even concede to these jurors that he was wealthy," Waters said. "And that was sort of the idea, was to get him talking about himself and about his life but then to, first of all, hammer home the financial aspects of this case and the many lies that he had told to people that trusted him and then move into the specifics of his new story that he was now telling the world for the first time, at least publicly. And I think that's very compelling and ultimately was convincing to the jury."

When asked about the jury only taking three hours to reach a verdict, Waters said: "We presented a very compelling and strong case, and I think that it didn't take them long to figure this out."

"They looked him in his eyes, as much as I've had the chance to do, and realized who this person really was." he added. “And I think that really was the final thing that led this jury to come to the right conclusion."

Waters said he hopes to see a "just sentence from the judge" on Friday morning.

"I do think that, in the end, we will have a just result for Maggie and Paul, who again we cannot forget in all of this," he said. "That's what this is really about and, thankfully, they had a voice yesterday when the jurors spoke."