CBS
Senior correspondent John Miller, a former assistant director of the FBI, reported this:
There is an individual in custody … he is not free to go.
He is a Saudi national who was near the scene of the blast. When the blast happened he began to run. Now, in context, a lot of people began to run. A civilian who thought he was acting suspiciously chased him down and tackled him and then turned him over to Boston police, saying, I saw this guy hanging around over there acting suspiciously. And then he ran. That may mean a lot, it may mean nothing at all.
Miller added that the man was fully cooperative but was denying any involvement in the bombing.