Allen Michael Martin, 28, of Walterboro, was arrested Tuesday night on two counts of unlawful conduct toward a child. He was taken to the Colleton County Detention Center.
His son, Aiden Martin, died from a gunshot wound on May 5.
The child was with his father at a Walterboro mobile home on Robinson Road about 11:30 p.m. May 4 when there was a "pop" sound from the kitchen and the child was found shot, according to an earlier report from Lt. Tyger Benton, spokesman for the Sheriff's Office.
There were several other adults reported to be at the residence.
The child was driven to Colleton Medical Center in his father's vehicle, and then he was airlifted to Medical University of South Carolina, where he died, said Benton.
Section 63-5-70 of the South Carolina code of laws says the charge of unlawful conduct toward a child addresses cases in which a guardian or parent places the child at unreasonable risk of harm, causes bodily harm to the child or abandons the child.
It is a felony charge with a maximum sentence of 10 years, the code says.
The boy's mother, Arika Williams of Walterboro, called for "justice" in a report on Live 5 News.
“There’s no way Aiden was in a house full of people, don’t nobody know what happened,” Williams told the television station.
Live 5 News reported that Aiden is the grandson of Gloria Williams, the woman who is awaiting sentencing after pleading guilty to kidnapping a baby from a Jacksonville, Florida, hospital in 1998 and raising the child as her own.
In its reporting on the kidnapping case, The Florida Times Union newspaper said Arika Williams is Gloria Williams' stepdaughter.