Speaker 1: ABC News exclusive for you here. Just one day after the inauguration, ABC News has learned there was a security breach at the US Capitol. Police officials say a Massachusetts man was discovered carrying a gun after he attended a tour of the Capitol building. ABC News Chief Justice Correspondent Pierre Thomas has all the details.

Speaker 2: Terry, police officials say this is a disturbing security breach that can never happen again. A 27-year-old man from Massachusetts who officials feared was having suicidal thoughts apparently was able to make his way through security at the US Capitol Visitor Center and take a full tour of a busy US Capitol armed with a 9-millimeter handgun. The breach occurred sometime between 1 and 2 PM Tuesday afternoon, with senators, Congress members, and members of the public all unaware of a potentially dangerous situation. Authorities say the man set off the magnetometers and was subjected to additional screening by a Capitol Police officer who apparently failed to detect the firearm. The officer, according to the Capitol Police, has been suspended pending a review of the incident. And we're also told that Capitol Police officers will now undergo mandatory refresher training on security screenings. One chairman of a congressional committee said he was, quote, severely disappointed. More to come, Terry.

Speaker 1: I'll bet. Pierre Thomas, thanks very much.