The alleged gunman in a mass shooting that killed five people in South Carolina — including a doctor and two of his grandchildren — was a former NFL player who had been treated by the slain physician, according to reports Thursday.

A fifth victim, maintenance worker James Lewis, 38, of Gastonia, was fatally shot outside the home, according to the York County Sheriff’s Office.

A sixth person, a second worker at the home who was not immediately identified, was hospitalized with a gunshot wound, sources told The Herald.

Adams, a Rock Hill native, was tracked down by police at his parents’ home — down the street from the gruesome shooting scene, the newspaper reported.

A motive in the mass shooting has not been released by authorities, The Herald reported.

Adams was convicted of several traffic charges in York County on Tuesday, one day before the mass shooting, including driving under suspension, The State reported, citing South Carolina records

He played 78 games in his six-year career, including seasons with Oakland and the New York Jets, as well as brief stints in New England and Seattle, according to a pro football reference website