Boston Mayor: Tsarnaev Brothers Acted Alone

Boston Mayor Thomas Menino told ABC's This Week that, as far as he knows, the Boston Marathon bombing investigation has not uncovered any suspects other than the Tsarnaev brothers. "All the information I have is they acted alone," he said, according to Politico. He also defended the decision to effectively turn Boston into a ghost town during the manhunt Friday in an effort to keep the public safe. He said a pipe bomb was found in Boston that day, and he had information about "other things going on." Elsewhere on the Sunday dial, per Politico and the AP:

• Police believe the Tsarnaev brothers were planning other attacks, Commissioner Ed Davis told CBS' Face the Nation, according to the AP. Authorities found an arsenal of weapons and homemade explosives at the scene of Friday's firefight.
• Massachusetts Gov. Deval Patrick told NBC's Meet the Press that surveillance video clearly places Dzhokhar Tsarnaev at the scene, the AP reports. "It does seem to be pretty clear that this suspect took the backpack off, put it down, did not react when the first explosion went off, and then moved away from the backpack in time for the second explosion," Patrick said. "It's pretty clear about his involvement and pretty chilling, frankly."
• Patrick also told Face the Nation that authorities believe the immediate threat has passed now that Tamerlan Tsarnaev is dead and Dzhokhar Tsarnaev is in custody.
• But, some alarming pronouncements: Former White House counterterrorism adviser Richard Clarke told This Week that other radicals will likely try copycat crimes, now that they've seen how easy it is to "close down a city, get the president of the United States to show up." And Rep. Bennie Thompson, who is on the House Homeland Security Committee, said on the same show that the government needs the public's help to spot potential radicals.
• Speaking of which, there was some blame tossed the FBI's way for failing to stop the Tsarnaevs. "This is at least the fifth case I'm aware of where the FBI has failed to stop someone," Rep. Peter King told Fox News Sunday. "This is the latest in a series of cases like this ... where the FBI is given information about someone as being a potential terrorist. They look at them, and then they don’t take action, and then they go out and commit murders." On CNN's State of the Union, Sen. Lindsey Graham echoed that, saying "either our laws are insufficient or the FBI failed."

(More Sunday morning talk shows stories.)