The star witness from the Alex Murdaugh murder trial is now delving into the mysterious 2015 death of Stephen Smith, asserting that someone “has a good idea who committed this crime.”

Appearing on Anne Emerson’s “Criminally Obsessed” podcast, forensic expert Kenny Kinsey, who testified for the prosecution during the 2023 Murdaugh trial, expressed his belief that crucial leads were overlooked in the initial investigation after evaluating the case evidence.

Stephen Smith, a 19-year-old nursing student and former classmate of Buster Murdaugh, was discovered lifeless on July 8, 2015, on a secluded road in Hampton County, South Carolina, not far from the Murdaugh family’s sprawling hunting grounds.

Smith, who was openly gay, had been walking on Sandy Run Road after his vehicle broke down when a motorist spotted his body and alerted authorities. He suffered a 7½-inch skull fracture, and his death was initially categorized as a hit-and-run by investigators.

In a poignant image, Stephen Smith is seen alongside his mother, Sandy Smith, at his high school graduation—a memory starkly contrasted by his tragic death on July 8, 2015, which was initially deemed a hit-and-run by South Carolina officials. (Findagrave.com)

Kinsey has meticulously combed through the original investigation files, scrutinized the results of a second autopsy, reviewed police interviews, and personally visited the location where Smith was found nearly 11 years ago.

He said his forensic analysis indicates Smith’s fatal injuries were connected to a vehicle but declined to detail specific wound patterns.

However, Kinsey emphasized that determining who was responsible falls to investigators.

“I don’t know the who,” he said. “That part comes from the investigation.”

A cross marks the spot where Stephen Smith was found dead in Hampton County, S.C., Feb. 28, 2023. Nineteen-year-old Stephen Smith’s body was found here in 2015. (Mark Sims for Fox News Digital)

During the podcast interview, Kinsey described what he called “missed opportunities” in the early stages of the case, saying delays and jurisdictional confusion can make cases harder to solve over time.

“Memories fade. People leave this earth,” Kinsey said. “Those missed opportunities — you don’t get that back.”

The investigation into Smith’s death was reopened in June 2021, just two weeks after Maggie and Paul Murdaugh were shot and killed at the family’s Colleton County hunting estate.

At the time, the South Carolina Law Enforcement Division (SLED) said it had uncovered information related to Smith’s death while investigating the Murdaugh murders but declined to provide details.

Stephen Smith’s body was exhumed over the weekend, and a second autopsy was performed as part of the investigation into his homicide.  (Findagrave.com/Courtesy of FitsNews)

In 2023, SLED announced that Smith’s death was being investigated as a homicide. His body was later exhumed, and a second autopsy was performed. The findings of that autopsy have not been publicly released.

Pathologist Dr. Michelle DuPre, who oversaw the second autopsy, previously told Fox News Digital that Smith’s injuries were consistent with being struck by an object attached to a vehicle traveling at a high rate of speed.

“Scientifically, medically and forensically, we know what happened, but we don’t know who did it,” DuPre said at the time.

For years, unsubstantiated speculation circulated publicly tying Smith’s death to members of the Murdaugh family.

Buster Murdaugh watches his father, Alex Murdaugh, testify during his double murder trial. (POOL)

Buster Murdaugh issued a statement in March 2023 denying any involvement and calling the allegations “baseless rumors.”

Kinsey told Emerson he saw no evidence linking the Murdaugh family to Smith’s death.

“I saw nothing that would make me even draw an inference that that’s to be true,” he said.

Stephen Smith’s mother has continued to push for answers as the case approaches a grim milestone.

July 8, 2026, will mark 11 years since the 19-year-old died.

Authorities have offered a $50,000 reward for information leading to arrests and convictions in the case. SLED has said the investigation remains active and ongoing.

Stepheny Price covers crime, including missing persons, homicides and migrant crime. Send story tips to stepheny.price@fox.com.