Sen. Lindsey Graham (R-S.C.), appearing Sunday on CNN’s “State of the Union With Candy Crowley,” said the FBI dropped the ball on Tamerlan Tsarnaev, the older of the two Boston Marathon bombing suspects.

In 2011, responding to concerns raised by the Russian government, the FBI looked into Tamerlan’s activities, but the FBI said its one interview with him did not turn up any terrorism concerns. A year later, Tamerlan spent six months in Russia, and the question is, with whom did he meet while there?

Sen. Graham said that anyone brought to the FBI’s attention by a foreign government should be red-flagged: “The ball was dropped in one of two ways: The FBI missed a lot of things is one potential answer, or our laws do not allow the FBI to follow up in a sound, solid way.