Capitol police identified the man as Michael Steven Gorbey, 38, and are charging him with a count of "felon in possession of a firearm." Other charges are pending, police said.

Officers spent several hours probing the contents of the green Chevy truck with Utah's colorful arch tags. But police were unsure late Friday where Gorbey obtained the truck, which also had a red hard cover for the truck's bed.

Terrance Gainer, the Senate sergeant-at-arms, told The Washington Post the man's vehicle had wires coming out of the glove box and propane tanks inside. Police used a robotic camera to see inside the vehicle, then destroyed items inside the car with a powerful water hose.

"We don't know if that vehicle belongs to him or not, but the vehicle is associated with him," Sgt. Kimberly Schneider told reporters.

Police said Gorbey, allegedly wieding the shotgun and shouldering the sword, was spotted in Lower Senate Park around 1 p.m. Friday and was tackled by Capitol Police officers. The park, near the three Senate office buildings, is located near Union Station, a busy train and subway station by the Capitol.

Police said the pickup truck was parked near the Brotherhood of Teamsters building, within the jurisdiction of Capitol Police but on the outskirts of the secured zone of the Capitol.

Since the Sept. 11, 2001 terrorist attacks, security at government buildings in Washington has been stepped up. Police do not allow large vehicles near the Capitol, barriers block close access to office buildings and extra patrols are visible at the White House and U.S.

Capitol.

The Senate emergency alert system was activated Friday afternoon after the man was spotted. Staffers in the buildings were not evacuated but couldn't access their vehicles in adjacent parking lots.

The U.S. Capitol and White House have been evacuated on occasion in recent years when assailants either jumped security fences or broke through to secure areas.

- The Associated Press contributed to this report.

tburr@sltrib.com