Gunman kills 9 then shoots himself in Alabama massacre.
At least four other people, including a child, were injured in the Alabama shootings.
The man burned down his mother's home, killed his grandparents, an uncle and aunt, and shot at apparent strangers on their porches as he drove by.
He then turned the gun on himself at a metals plant.
Frankie Lindsay, chief of police in Geneva County where five people were shot dead, said the man also fired at officers as they chased his vehicle in patrol cars.
He said the wife and child of a deputy sheriff in Geneva were among the dead.
Mr Lindsay added: "This is probably the worst incident in the state of Alabama that I know of.
I've been in this business for 33 years and this is the worst I've ever seen."
The afternoon of bloodshed began in Kinston, near the Alabama-Florida border, where the man burned down his mother's house.
He then headed east into Geneva County, where he shot and killed four adults and a child at a home in the nearby town of Samson. Then he killed one person each in two other homes.
The identities of all the victims were unknown, but the Coffee County coroner Robert Preachers said they included other members of the gunman's family.
The man turned the gun on himself after a police pursuit.
DISBELIEF: Shocked relatives of shooting victims comfort each other outside a house in Samson, Alabama; RAMPAGE: Police at the scene of one of the shooting