In September 2011, the CIA had requested to place Tamerlan Tsarnaev and his mother Zubeidat Tsarnaeva to be added on the list after the Russian government expressed concerns that both had become religious militants.
About six months prior, the FBI had investigated both mother and son, also at Russia's request. The FBI found no ties to terrorism during their investigation.
Since the Boston Marathon attack, Zubeidat Tsarnaeva has appeared on television, saying her sons could never have been behind the bombings. She claims they were framed.
The revelation surrounding Zubeidat Tsarnaeva comes on the same day that her younger son, the surviving Boston Marathon bombings suspect Dzhokhar Tsarnaev, was transferred from a civilian hospital to a federal medical detention center in Devens, Mass., according to the U.S. Marshals Service.
A heavily armed convoy transported 19-year-old Dzhokhar Tsarnaev to the Federal Medical Center (FMC) Devens, which is a federal prison for male inmates requiring specialized or long-term medical or mental health care.
Meantime, police said Tsarnaev has revealved details about a spur-of-the-moment plan to attack Times Square in New York City with his brother, Tamerlan Tsarnaev. They were planning to use their remaining pipe bombs and pressure-cooker bomb.
Authorities said the brothers wanted to drive to New York last Thursday, but their plan fell apart when the vehicle they carjacked was low on gas. When they stopped at a gas station, the man they took hostage escaped and called police.
That eventually led to a shootout and the death of the older brother, Tamerlan Tsarnaev.
The younger Tsarnaev is listed in fair condition, recovering from neck, hand and leg injuries. Officials would not comment on whether authorities plan to add more charges based on the alleged plot to attack New York City.
Dzhokhar Tsarnaev could face the death penalty for the deadly Boston Marathon blasts that killed three spectators and sent more than 260 people to the hospital.
More details are also emerging about the suspects' movements in the days leading up to the Boston attack. Cab driver Jim Duggan said he gave the brothers a ride the day before the bombings and he thinks the suspects actually were carrying one of the bombs with them at the time. He said the men almost forgot their backpack in the back of his cab.
"The most chilling thing is remembering picking up the backpack and how heavy it was. Man, I could have had the bomb in my hands," said Duggan.Investigators are looking into the possibility the Tsarnaev brothers had actual military-style training to help them build those bombs and didn't simply learn from the Internet.
The Associated Press contributed to this report.