WHEELING, W.Va. -- A retired police officer armed with an assault weapon and a handgun fired up to two dozen shots at a U.S. courthouse in West Virginia on Wednesday before police returned fire and killed him, authorities said.
Wheeling Police Chief Shawn Schwertfeger identified the gunman as Thomas J. Piccard, 55, of Bridgeport, Ohio. He was a retired Wheeling police officer.
Schwertfeger did not say whether Piccard used both weapons during the assault on the Wheeling Federal Building or speculate on a motive. Officials said they had no knowledge of any sort of note left behind by Piccard.
Three on-duty security officers were injured by flying debris during the onslaught, he told a news conference.
Wheeling Mayor Andy McKenzie said police who briefed him earlier Wednesday told him that Piccard was a 20-year-plus veteran of the force who retired 13 years ago.
Investigators were seeking a search warrant for Piccard's home in hopes of determining a motive and if he acted alone, said Chief Deputy Mike Claxton of the U.S. Marshals Service in northern West Virginia.
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 a man later identified as Piccard 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.
The building houses a variety of courtrooms and related offices, including those for judges, prosecutors and law enforcement.
Officials said it was too early to tell whether Piccard was targeting anyone in the building or what his motive may have been.
"That's still trying to be determined," said Bob Johnson, the assistant special agent in charge of the FBI's Pittsburgh office.
People inside the building ducked under desks as the shots struck the building and shattered windows.
U.S. Attorney Bill Ihlenfeld said shots were fired into at least three rooms in his office on the building's second floor. He described hearing gunshots, then panic among staff.
"Members of my staff were crawling on the floor or running from office to office telling people to get away from the windows," he said.
Ihlenfeld said he knew Piccard from 1997 when he started working in the city prosecutor's office until the officer retired in 2000. He said he had no reason to believe his office was targeted, and that Piccard was not under any sort of investigation by federal authorities.
"There was nothing about my relation with him or anything that I observed in dealing with him ... to cause me to think anything like this would happen," he said.
About 40 percent of Ihlenfeld's staff was furloughed because of the federal government shutdown, so many weren't working on Wednesday.
"To be honest, the security plans in place to deal with a situation like this don't work when we don't have everybody there," he said, without elaborating.
Carla Webb Daniels told media outlets she was in her attorney's office nearby when she heard loud gunshots. She saw the gunman fire from a bank parking lot across the street.
"I was so nervous, I couldn't believe it," Daniels said. "People were scared and were banging on the doors asking to be let in."
Piccard's body will be sent to the Medical Examiner's Office in Charleston for an autopsy. Meanwhile, officials continued to search his four-door sedan that he drove to the scene and his trailer across the river in Bridgeport, Ohio.
Johnson said a bomb squad would clear the home before investigators go in as a precaution.
The three-story gray federal building remained cordoned off Wednesday night, surrounded by a heavy police presence in the city along the Ohio River in West Virginia's northern panhandle about 60 miles southwest of Pittsburgh.
Most people were going about their evenings, eating at local restaurants in the small city of about 28,000 with an older downtown with stone buildings, banks and coffee shops. Only a few stopping to gaze at the courthouse.
David Wohlfeil, the owner of the Metropolitan City Grill near the courthouse, said he ran outside after he heard the first round of shots. He heard two more volleys of gunfire then ran back inside.
"I told everyone to get in the basement and then called 911," he said, adding that police arrived while he was on the phone.
Wheeling has been hit by layoffs in the steel industry and its population dropped by 9.3 percent from 2000 to 2010 to about 28,500 people.
McKenzie said the shooting underscores the fact that even small cities like Wheeling are "not immune to national problems."
"Things like this aren't just happening in large cities, in this country we need to do a better job on mental health," he said.