A Massachusetts man was found carrying a gun after taking part in a tour of the US Capitol on Tuesday as he left the nearby Library of Congress, police officials told ABC News on Thursday.
Washington authorities Police in Carlisle, Massachusetts, warned Monday that a man who had expressed suicidal thoughts on social media was on his way to Washington.
The U.S. Secret Service and Washington, D.C. Metropolitan Police located the man at a Washington hotel early Tuesday and interviewed him, sources said. They searched for a gun and found no weapon and took no further action at that point, they said.
Later that day, the man passed the Capitol Police magnetometer screen and entered the Capitol Visitor Center. The magnetometer sounded the alarm and “an officer conducted a second-hand search, and the man was taken into the building,” according to a statement from the U.S. Capitol Police.

The US Capitol in Washington, DC on December 10, 2024.
Al Drago/Bloomberg via Getty Images, FILE
After getting past security, Capitol Police were alerted to his presence and sent out a bulletin to look for the man. He was later located outside the Library of Congress after completing his full tour of Congress and found to have a 9 mm handgun in his waistband, law enforcement sources said.
Authorities said the suspect was arrested for: “Unlawful activity, carrying a handgun without a license, possession of an unregistered firearm, illegal possession of ammunition and resisting arrest.” The case is currently with the U.S. Attorney’s Office, a Capitol Police statement said.
The officer who performed the screening at the magnetometer in the Capitol Visitor Center “is on hold while the USCP Office of Professional Responsibility conducts an administrative investigation into the officer’s conduct of that search.”
There is no indication that he intended to harm Congress, according to Capitol police. But sources told ABC News that a man who was possibly suicidal was able to make a full tour of Congress, with members of the public and around Congress with a gun.
“A full review of this incident has already been ordered, as well as mandatory refresher training on security screening, so this will not happen again,” Capitol Police said in a statement.
Members of Congress were briefed on the situation on Thursday.