(NewsNation) — South Carolina authorities reinvestigating the death of a teenager found dead in the middle of a road in 2015 no longer believe he was killed in a hit-and-run accident, according to the attorney representing the family of Stephen Smith.

“This is what I’ve been waiting for,” said Smith’s mother Sandy, who has been fighting for more answers since her son’s death.

Officials initially determined it was most likely that Smith was the victim of a hit-and-run in July 2015, a theory his family doubted from the start. Police said he was walking along the road after running out of gas, but investigators found no skid marks or car debris, and the 19-year-old’s loosely-tied shoes were still on his feet, attorneys have said.

Stephen’s mother has been fighting for more answers ever since.

In an exclusive prime-time interview Tuesday on NewsNation’s “CUOMO,” Sandy Smith said she was elated by the news.

“I’m still in shock,” she said.

The investigation into Smith’s death was reopened nearly two years ago after the June 7, 2021, killing of Maggie and Paul Murdaugh, the wife and son of Alex Murdaugh who was convicted of their murders.

Though there is no known evidence linking any Murdaugh family members to Smith’s death, Richard “Buster” Murdaugh, Alex’s surviving son, issued a statement Monday denying rumors he was involved. Buster and Stephen were classmates at the time of the Stephen’s death.

“This has gone on far too long. These baseless rumors of my involvement with Stephen and his death are false,” he said in part. “I unequivocally deny any involvement in his death, and my heart goes out to the Smith family.”

Eric Bland, an attorney representing the Smith family, said the chief of the South Carolina Law Enforcement Division (SLED) relayed the new death conclusion in a phone call with him Tuesday.

“Chief (Mark) Keel said that he will join us in our exhumation of Stephen Smith, that we will cooperate together in a de facto partnership with what our experts will uncover and analyze and uncover after Stephen is exhumed,” Bland said. “It’s a golden day for this mother that her son was not killed on a highway as they indicated in the certificate of death.”

Ronnie Richter, another attorney for Stephen Smith’s family, said on “Dan Abrams Live” Monday night that his team’s involvement in the case has “nothing to do” with Buster Murdaugh.

“Our involvement in, our participation in this case, has nothing to do with Buster Murdaugh. It does have everything to do with finding the ultimate truth and seeking the truth without regard to who’s involved,” Richter said.

Sandy Smith is using more than $80,000 raised through a GoFundMe campaign to launch an independent investigation and autopsy into her son’s death.

“I really don’t know why they did what they did. I just knew in my heart that what they were telling me was not true,” Sandy Smith said of the initial findings and ruling. “I believe (Stephen) was beaten to death.”

Bland and Richter said in a news release Tuesday night that SLED officials did not need an exhumation to make the new death determination. It adds state police were waiting for the conclusion of Alex Murdaugh’s double-murder trial to make an announcement “out of concern that witnesses would not be as forthcoming under the Murdaugh sphere of influence.”

SLED did not immediately respond to a request for comment.

“Chief Keel told me that they believe there is a small circle of people that have information and that they believe they can now talk and feel free because the yoke of the Murdaughs as a result of the verdict is now off them,” Bland said.

Stephen Smith was studying to be a nurse at the Orangeburg-Calhoun Technical College, hoping to eventually become a doctor. On July 8, 2015, he was on his way home from school when he ran out of gas. His car was found down a dark rural road in Hampton County, South Carolina, with the gas cap off.

Three miles away, Smith’s body was found in the middle of the road with no skid marks or other physical evidence that a car had hit him. A special accident investigation team looked at the case and determined it was a homicide, but a pathologist disagreed, saying he likely died from being hit in the face by the mirror of a passing car.

The Murdaugh name came up in initial investigations. Alex Murdaugh and his brother Randy came to the scene of Smith’s death, though it’s unclear why they were there.

According to Sandy Smith, Randy Murdaugh called the family following Stephen Smith’s death, offering to help however he could. However, his law firm has since disputed that, putting out a statement denying it ever happened.

No matter who may have been involved, Sandy Smith just wants justice for her son.

“He was so bright and so funny,” Smith said. “I just always remember that beautiful smile and them dimples.”

NewsNation staff members Stephanie Whiteside, Paige Lobdell and Rich McHugh contributed to this report.