The shootings began late in the afternoon in Samson. The shooter killed five people in one home and one each in two other homes.
The gunman also shot at a state trooper's car, striking the vehicle seven times and wounding the trooper with broken glass.
He then killed someone at a Samson supply store and another person at a service station, the safety department said.
Police pursued him to Reliable Metal Products just north of Geneva, about a dozen miles southeast of Samson, where he fired an estimated 30 rounds. One of the bullets hit Geneva Police Chief Frankie Lindsey, who was saved by his bullet proof vest, the safety department said.
The statement says the gunman then went in the plant and shot himself. His name was not released.
The gunman had worked at Reliable Metal, said state Rep. Warren Beck, a Republican whose district includes Geneva.