(CBS/AP) WHEELING, W. Va. -Wednesday afternoon before security officers returned fire and killed him, is a former Wheeling police officer, several reports say.
One security officer in the Wheeling Federal Building was injured by flying debris, but there were no other injuries, said Chief Deputy Mike Claxton of the U.S. Marshals Service in northern West Virginia.
The gunman was hospitalized with life-threatening injuries and later died, Claxton said.
Claxton said investigators were seeking a search warrant for the gunman's home in hopes of determining the motive and if he acted alone.
Asked if the gunman had any beef with the U.S. government, Claxton said, "We're really digging hard at this point to find out."
Claxton said the man began firing from a parking lot across from the federal building. "He was observed in the parking lot very quickly after the first shots were fired," he said.
CBS affiliate WDTV reports witnesses said it appeared the gunman was shooting at the building itself.
The building houses a variety of courtrooms and related offices, including judges, prosecutors and law enforcement.