A manhunt was underway during the night from Tuesday to Wednesday for the suspected killer of eight people in rural Virginia, dpa reported.
The suspect as been named as Christopher Speight, 39, of Appomattox, Virginia, and is considered by police to be armed and dangerous.
He is believed to be cornered by a force of 150 police officers in a wooded area near his home, Virginia State Police said.
Two of the victims of the shooting in the town of Appomattox, about 300 kilometres south-west of Washington, were Speight's wife and son, according to a local government official quoted on the website of the Daily Progress newspaper of Charlottesville, Virginia.
No details were issued about the six other victims.
In the course of the incident, the suspect allegedly shot at a police helicopter. The aircraft was disabled but no one of the passengers was injured.