(NewsNation) — As Alex Murdaugh sits in prison serving two consecutive life sentences for killing his wife Maggie and son Paul, another mystery still hangs over the Murdaugh family.

It’s the death of 19-year-old Stephen Smith, who was found dead in the middle of a road in 2015. His death was ruled a hit-and-run, but the case has since been reopened by state authorities.

Speculation has swirled that Buster Murdaugh’s, Alex’s surviving son, may have somehow been involved, despite any evidence. Murdaugh family attorney Jim Griffin called rumors that the Murdaugh family was involved in the death “vile” and defamatory.

“There is a significant amount of vile information … absolutely defamatory information linking Buster to Stephen Smith’s death,” Griffin said Monday on “CUOMO.” “He is being totally harassed, and this story just keeps getting in the way of his life, and it’s time for that to come to a close.”

Earlier in the day, Buster Murdaugh released a statement denying what he called “baseless rumors” that have interfered with his life.

There has been no known evidence that links the Murdaugh family to Smith’s death; however, the South Carolina Law Enforcement Division announced shortly after the deaths of Paul and Maggie that it was reopening the investigation due to information it had received during a separate investigation into the June 2021 shootings.

Buster Murdaugh was the same age as Stephen Smith and his twin sister. The two went to school together, and Buster’s name often came up in connection with the Stephen Smith case.

Although police determined Smith’s death was a hit-and-run, Smith’s mother, Sandy Smith, believes her son was killed intentionally. Smith’s family has raised enough money for an independent exhumation and autopsy.

Expressing sympathy for the Smith family, Griffin said they deserve answers but rejected the notion that his client had anything to do with Stephen’s death.

“Miss Smith is entitled to those answers, and if anyone knows grief and can share grief, it’s Buster Murdock, who shares similar grief as Miss Smith. I mean, there’s no greater grief than losing a child, but I can tell you there’s probably no greater grief than losing a mother and a brother to a brutal murder,” Griffin said. “This is not about Miss Smith; this is about Buster Murdock trying to move move forward and live his life in private without having to defend himself.”

NewsNation writer Taylor Delandro contributed to this report.