SLED said it was opening an inquiry into Smith's death "based upon information gathered during the course of the double murder investigation."
Investigators said in 2015 that it appeared Smith, 19, was hit by a vehicle while standing outside of his car after it had run out of gas, reported NBC affiliate WCBD in Charleston. The incident occurred in Hampton County, about 15 miles from the Murdaugh property known as Moselle.
Initially, Smith was found with a "defensive wound" on his hand, according to an investigator's report obtained by The Island Packet, and a homicide investigation was opened.