"Tamerlan was counseled by the FBI for three, five years," she said. "They knew what my son was doing. They knew what actions and what sites on the Internet he was going. How could this happen? How could they – they were following every step of him, and they're telling today this is a terrorist act."
Zubeidat Tsarnaeva told CNN Friday in an interview that the FBI has been keeping tabs on her son for three to five years and wondered how the U.S. government could have allowed him to go ahead with his plans if they were watching him so closely.