John Pettiway III, 21, of the Selma area, was arrested and charged with murder, robbery with a dangerous weapon and felony conspiracy.
Police said he was caught in Greenville.
The shooting happened around 1:30 a.m. on November 14, at a Scotchman gas station near the intersection of NC Highway 210 and Interstate 40.
Robbers shot and killed 23-year-old Joseph Bowling, who reportedly stepped in front of a gun aimed at his mother, who worked at the store.
A week after the incident, officials said Bobby Mclean Jr. turned himself in at the Johnston County Sheriff's Office. Mclean was charged with murder, robbery with a dangerous weapon, felony conspiracy and possession of a firearm by a convicted felon. Mclean is being held in the Johnston County Jail under no bond.
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One of the suspects, 19-year-old Manuel Patterson, was in jail on a robbery charge when he was charged with murder and robbery at the Scotchman.
Pettiway is being held in the Johnston County Jail under no bond.
Authorities also said the same robbers are suspected in two other convenience store holdups in the area.