Mark Keel, chief of South Carolina’s Law Enforcement Division, said that “in the end Paul was a little detective,” likely alluding to Paul Murdaugh’s cellphone video that placed his dad, Alex Murdaugh, at the crime scene minutes before Paul and his mother were murdered.

“SLED agents have worked tirelessly for the past nearly 21 months to ensure justice was served for Maggie and Paul,” Kent said in a statement Friday. “It was all done under constant pressure and scrutiny. I want my folks to know how incredibly proud I am to be their Chief.”

He added, “Today is not the end, it’s the next step in the long road to justice for every person who has been victimized by Alex Murdaugh.”

“This case serves as notice to anyone who aided or assisted Alex Murdaugh in committing any crime that justice will be sought,” Kent said.

Alex Murdaugh faces about 100 other charges for allegations ranging from money laundering to staging his own death so his surviving son could cash in on his $10 million life insurance policy. Alex Murdaugh has admitted to stealing money from clients.

Defense attorney Jim Griffin said Alex Murdaugh's surviving son, Buster, speaking on his father’s behalf at Friday's sentencing hearing would not have made a difference in the sentence, and only would have put Buster through more trauma.

Defense attorney Dick Harpootlian stood by putting Alex Murdaugh on the stand during the trial.

"There was no choice, because he had been made out to be a monster ... he had to try to push back on that," Harpootlian said. "Without taking the stand, he was toast."

"He had to take the stand to explain the video," he said, referring to the cellphone video placing Alex Murdaugh at the scene minutes before the murders.

Harpootlian said he wouldn't change anything about how the defense presented its case.

Harpootlian said the prosecution focused on Alex Murdaugh's character, casting him as a thief and a liar.

"This jury had to think he was a despicable human being and not to be believed. So it was about character, wasn't about motive," he said.

Harpootlian said the defense will file an appeal in 10 days.

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."

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."