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."

A juror who voted to convict Alex Murdaugh on Thursday told ABC News in an exclusive interview that the piece of evidence that convinced him the disgraced lawyer was guilty, was the cellphone video placing Murdaugh at the scene minutes before the murders of his wife and youngest son.

"I was certain it was [Murdaugh's] voice," Craig Moyer, a carpenter, said as he recalled the background voice he heard during his first watch of the video captured by Murdaugh's son. The video was taken at the family's dog kennels by Paul Murdaugh, 22, who later that night was brutally murdered along with his mother Margaret, 52.

"Everybody else could hear [Murdaugh's voice] too," Moyer said, referring to the other jurors.

Moyer's comments to ABC News' Eva Pilgrim came just hours after he voted to convict Murdaugh, concluding the small-town South Carolina saga which documented the downfall of a powerful attorney from a family which for generations exuded power over the state’s Lowcountry region.

Please watch "Good Morning America" on Friday at 7 a.m. ET to see more of Moyer's interview and ABC News' coverage of the Murdaugh case.

After nearly three hours of deliberations, a jury reached a guilty verdict Thursday in the double murder trial Alex Murdaugh, a disgraced South Carolina attorney who was charged with the murders of his wife and their younger son at their rural hunting estate in June 2021.

The bodies of Margaret "Maggie" Murdaugh, 52, and Paul Murdaugh, 22, were found dead from multiple gunshot wounds near the dog kennels at the family's estate in June 2021, authorities said.

Alex Murdaugh, 54, who called 911 to report the discovery, was charged with their murders 13 months later.

Jurors -- and the packed gallery -- heard testimony from dozens of witnesses since the trial started on Jan. 23 in the Colleton County Courthouse in Walterboro, South Carolina.

Here's a look at five key moments from the high-profile trial.

A string of bloody killings and mysteries involving a prominent South Carolina family has been filled with a wild chase full of twists and turns -- culminating in a murder conviction against the family’s patriarch.

At the center of it is Alex Murdaugh, 54, a former lawyer who comes from a legacy of prominent attorneys in South Carolina, where three generations of the family had been state prosecutors in the Hampton County area for more than a century.

The saga began when his youngest son, Paul, was involved in a fatal boat crash in 2019. A year and a half later, Murdaugh's wife, Margaret "Maggie" Murdaugh, 52, and Paul, 22, were found fatally shot on the family's rural hunting estate.

Since then, there have been curveballs in the investigation -- including Alex Murdaugh's alleged money misuse that led to his disbarment, an admitted opioid addiction, an assisted-suicide attempt involving an alleged $10 million insurance fraud scheme and a high-profile murder trial.

Here's a timeline of the key events in the Murdaugh murders and scandals.