Local authorities say McLendon was armed with two assault weapons with large capacity magazines and another firearm.
At a press conference today, a local official said McLendon was employed at a food company at the time of the shooting and had earlier worked briefly as a police officer in the city of Samson.
Coffee County Coroner Robert Preachers says the bloodshed began when McLendon shot his mother and the family's dogs before burning her home. Preachers said McLendon piled up the bodies of his mother and her dogs, poured gasoline on them and lit it. He then drove to Samson, where a number of the gunman's relatives were killed.
Also killed were the wife and 18-month-old child of Geneva County sheriff's deputy Josh Myers, who was responding to the shooting. Myers' four-month-old baby survived the shooting spree and is hospitalized in stable condition.
McLendon ended the day in a shootout with police at a company where he had once worked and was found dead from a self-inflicted gunshot wound.
An investigation into the shootings continues.