Zubeidat Tsarnaeva, who had reportedly become more militant in her Muslim faith around the same time as her son, Tamerlan Tsarnaev, was added to the classified intelligence database known by the acronym TIDE at the CIA’s request. Two key lawmakers said authorities now want to know if she helped put her son, who died a week ago following a shootout with police in Massachusetts, on the road to radicalism.

“She is a person of interest that we’re looking at to see if she helped radicalize her son, or had contacts with other people or other terrorist groups,” Rep. Dutch Ruppersberger, D-Md., the top Democrat on the House Intelligence Committee, told reporters.

Rep. Michael McCaul, R-Texas, who chairs the House Homeland Security Committee, also pointed to Zubeidat as someone who may have led Tamerlan down the path toward Islamic extremism.

“The mother in my judgment has a role in his radicalization process in terms of her influence over him (and) fundamental views of Islam,” McCaul said.

Tsarnaeva was put on the database after Russia told the CIA the mother and son were religious militants preparing to travel to Russia, the AP reported. It has already been widely reported that Tamerlan Tsarnaev, the 26-year-old suspect who died after a shootout with police in Massachusetts a week ago, was on the list.

The Terrorist Identities Datamart Environment database contains between 500,000 and 1 million names of people on the radar of various national security agencies, but a person’s presence on the list does not automatically mean he or she is suspected of terrorist activity and does not automatically subject them to surveillance, security screening or travel restrictions.

Zubeidat Tsarnaeva said she was not planning to travel to the U.S. in the wake of one son’s death and the other’s arrest, though her ex-husband was planning to. But she told Fox News Friday that her ex-husband, Anzor Tsarnaev, was being taken Friday to a hospital in Moscow to treat what she described as “nerves, head, stomach and elevated blood pressure.”

Anzor Tsarnaev had planned to fly to the U.S. from the semi-autonomous southern Russian republic of Dagestan as early as Thursday. His sons, 26-year-old Tamerlan and 19-year-old Dzhokhar Tsarnaev, are responsible for detonating two bombs at the Boston Marathon last week, killing three and injuring more than 180 people, according to federal law enforcement officials.

In a press conference on Thursday, Anzor Tsarnaev said he was coming to the U.S. to bury his eldest son and “find out the truth” — while his ex-wife, who sat beside him, questioned whether the attack even took place.

Tamerlan Tsarnaev, believed to be the mastermind behind the attacks, died in a fierce gun battle with police four days after the deadly attacks. His body has not yet been claimed.

Dzhokhar Tsarnaev, who was wounded in the gun fight with authorities, has been transported from the Beth Israel Deaconess Medical Center to the Federal Medical Center at Fort Devens in Ft. Devens, Mass., U.S. Marshals Service spokesman Drew Wade said. He faces a charge of use of a weapon of mass destruction that could carry the death penalty.

Speaking to reporters from the mountainous southern Russian region of Dagestan, Anzor Tsarnaev said Thursday that he still isn’t convinced his sons set the bombs on April 15.

“I am going to the United States,” Tsarnaev said, punctuating his words by banging on the table. “I want to say that I am going there to see my son, to bury the older one. I don’t have any bad intentions. I don’t plan to blow up anything.”

The suspects’ mother, who has an outstanding warrant for shoplifting, is apparently not planning to make the trip. She expressed sympathy for the victims, yet questioned whether the bombing occurred, suggesting red paint was used to simulate blood on Boston’s Boylston Street.

“That’s what I want to know, because everybody’s talking about it — that this is a show, that’s what I want to know,” she told reporters. “That’s what I want to understand.”

The press conference Thursday came hours before New York City Mayor Michael Bloomberg announced that the two planned to detonate their remaining explosives in New York’s Times Square.

Anzor Tsarnaev — who has previously said he believes his sons were set up, despite Dzhokhar’s alleged confession from his hospital bed — said he planned to leave as early as Thursday.

“I am not angry at anyone,” he said. “I want to go find out the truth.”

But Zubeidat Tsarnaeva told Fox News that it will take her ex-husband at least two days to decide whether he is able to make the trip. She said the two were en route to a hospital in Moscow and will make further decisions about travel from there.

Zubeidat Tsarnaeva remains wanted on felony shoplifting and property damage charges in Massachusetts, according to court officials, and is concerned she could be arrested. Tsarnaeva said she had been assured by lawyers, however, that she would not be.

She said she now regrets moving her family to the United States.

“I thought America was going to, like, protect us, our kids, it’s going to be safe,” Zubeidat Tsarnaeva told reporters. “But it happened, opposite. My kids just — America took my kids away from me.”

Anzor Tsarnaev told reporters that Tamerlan stayed with him in Makhachkala, Dagestan’s capital, during a trip his eldest son made in January 2012. Tsarnaev said they visited relatives in Chechnya and worked on an apartment in Makhachkala, but stressed that they were always together, including during trips to mosques. Tamerlan had made the trip primarily to obtain a Russian passport, he said.

Anzor Tsarnaev, who said his relatives were receiving threats in Dagestan, said Tamerlan never showed particular interest in the plight of the Chechen people or its two recent wars.

On Wednesday, Anzor Tsarnaev confirmed to Fox News that FBI and Russian authorities had visited him, adding that FBI officials were polite while asking him questions.

The Tsarnaev family emigrated to the U.S. a decade ago, but both parents returned to Russia last year. Dzhokhar Tsarnaev became a U.S. citizen last year, but Tamerlan had not yet earned citizenship.

Also Thursday, Russian President Vladimir Putin said the bombings should spur stronger security cooperation between Moscow and Washington, adding that they also show that the West was wrong in supporting militants in Chechnya.

“This tragedy should push us closer in fending off common threats, including terrorism, which is one of the biggest and most dangerous of them,” Putin said during his annual call-in show on state television.

Putin warned against trying to find the roots for the Boston tragedy in the suffering endured by the Chechen people, particularly in mass deportations of Chechens to Siberia and Central Asia on Soviet dictator Josef Stalin’s orders.

“The cause isn’t in their ethnicity or religion, it’s in their extremist sentiments,” Putin said.

Fox News’ Amy Kellogg and The Associated Press contributed to this report.

The White House stressed that this was not enough to confirm how the nerve gas was released — though acknowledged it is “very likely” to have originated with the regime of Bashar Assad — and pressed the United Nations for a “comprehensive” investigation. The letter from the White House director of the Office of Legislative Affairs to leading members of the Senate Armed Services Committee said the assessment was based in part on “physiological samples.”

Secretary of State John Kerry further confirmed that there were two documented instances of chemical weapons use.

The assessment is likely to prompt calls for more serious consideration of intervention. President Obama has said the use of chemical weapons would be a “game-changer” in the U.S. position on intervening in the two-year-old Syrian civil war. Obama said last August that “a red line for us” would be the movement or use of chemical weapons, adding “that would change my calculus.”

Sen. John McCain, R-Ariz., suggested Thursday the “red line” had been crossed. Sen. Bob Corker, R-Tenn., also said the assessment is “deeply troubling and, if correct, means that President Obama’s red line has certainly been crossed.”

But Caitlin Hayden, a spokeswoman for the White House National Security Council, said more information is needed.

“Precisely because the president takes this issue so seriously, we have an obligation to fully investigate any and all evidence of chemical weapons use within Syria,” she said in a statement. “That is why we are currently pressing for a comprehensive United Nations investigation that can credibly evaluate the evidence and establish what took place. We are also working with our friends and allies, and the Syrian opposition, to procure, share and evaluate additional information associated with reports of the use of chemical weapons so that we can establish the facts.”

Asked if this crossed a “red line” for the U.S., Hagel likewise said they are still trying to assess.

“It violates every convention of warfare,” he said.

Sources say the Russians contacted the FBI once in March 2011, and several months later they contacted the CIA about Tsarnaev.

In October 2011, the CIA sent information to many federal agencies and to “the watchlisting system” about him, the sources say. That step ultimately put him on the vast TIDE database of people potentially tied to terrorism cases.

The FBI has said previously that it was told Tsarnaev was a “follower of radical Islam” and was preparing to travel to a foreign country to join unspecified underground groups. The FBI said that it responded by interviewing Tsarnaev and family members, but found no terrorism activity.

In early 2012, Tsarnaev would travel to Russia for six months. The nature of that trip is still unclear.

Two top Republican senators are now calling for a Senate Homeland Security Committee hearing on the Boston Marathon bombings, as lawmakers question whether enough was done to prevent the attack.

Sens. John McCain, R-Ariz., and Kelly Ayotte, R-NH, requested the hearing Wednesday, saying “it has become increasingly apparent that more questions need to be answered regarding the failure to prevent this tragedy.”

The senators cited the reporting by Fox News and others that Russian officials contacted the U.S. government at least twice in 2011 with concerns about Tsarnaev, the Chechen who two years later would carry out last week’s deadly bombing of the Boston Marathon, as an example of an instance that merits further investigation.

“In a string of apparent intelligence-sharing lapses, Tamerlan Tsarnaev was able to slip through the cracks and carry out this devastating attack,” the senators said.

Authorities suspect Tsarnaev, 26, and his younger brother, Dzhokhar Tsarnaev, of using improvised explosives to kill and maim runners and spectators near the finish line of the Boston Marathon. Three people were killed and more than 200 injured in the April 15 attack.

Tamerlan Tsarnaev was killed days later in a shootout with police. His 19-year-old brother escaped but was captured alive Friday night and now faces a charge of use of a weapon of mass destruction that could carry the death penalty.

The brothers immigrated to the United States about a decade ago with their family. Dzhokhar Tsarnaev became a U.S. citizen last year, but Tamerlan had not yet earned citizenship.

Senators, after being briefed on the case Tuesday, said the U.S. government had “multiple contacts” with Russia about the older Boston bombing suspect, but those lawmakers wouldn’t offer any more details.

Fox News was told the FBI tried to determine if Tsarnaev had any ties to terrorism, but those efforts apparently proved inconclusive.

“We did everything we could,” one FBI source said, and their assessment was based on the “totality of the evidence.”

The FBI insists, despite suggestions to the contrary, that it was contacted only once by the Russians about Tsarnaev.

Rep. Dutch Ruppersberger, D-Md., said Wednesday that the U.S. made three inquiries with Russia about Tsarnaev and got no response.

Lawmakers and investigators are taking a close look at Tsarnaev’s trip to Russia in January 2012. His father says his son stayed with him in Dagestan.

Despite violence there, Anzor Tsarnaev said Sunday that his son did not want to leave and had thoughts on how he could go into business. But the father said he encouraged him to go back to the U.S. and try to get citizenship. Tamerlan Tsarnaev returned to the U.S. in July.

His mother said that he was questioned upon arrival at the airport in New York.

“And he told me on the phone, ‘Imagine, mama, they were asking me such interesting questions as if I were some strange and scary man: Where did you go? What did you do there?'” Zubeidat Tsarnaeva recalled her son telling her at the time.

Fox News’ Mike Levine and Catherine Herridge and the Associated Press contributed to this report.

The letter was sent Saturday by the House Committee on Homeland Security to Homeland Security Secretary Janet Napolitano, National Intelligence Director James Clapper and FBI Director Robert Mueller.

In the letter, Committee Chairman Rep. Mike McCaul says bombing suspect Tamerlan Tsarnaev appears to be the fifth person since 9/11 to participate in a terror attack, despite being under FBI investigation.

McCaul, R-Texas, said the incidents “raise the most serious questions about the efficacy of the federal counter terrorism efforts.”

Tsarnaev, 26, was killed early Friday morning in a police shootout. His 19-year-old brother, Dzhokhar Tsarnaev, was captured by police that night and remains in the hospital.

The older Tsarnaev was interviewed by the FBI in 2011 before a six-month overseas trip, including time in Russia. In addition, he posted jihadist material on his social media site.

On Saturday, two U.S. law enforcement officials said the FBI was acting on information from the Russian intelligence security service that Tamerlan Tsarnaev was a follower of radical Islam.

“Yet Tsarnaev remained at liberty in this country to conduct the Boston attack, and it took days to publicly identify him as a suspect,” wrote McCaul, who wants the information by Friday.

Rep. Peter King, R-N.Y., a committee member who also signed the letter, asked on “Fox News Sunday”: “Why didn’t the FBI go back and look at this?”

Still, the agency got some bipartisan support Sunday for its intelligence work and finding the bombing suspects.

“The FBI did its due diligence” Rep. Mike Rogers said on NBC’s “Meet the Press.”

Rogers, R-Mich., a former FBI agent, also suggested Tsarnaev could have made overseas trips under an alias.

Illinois Democratic Sen. Dick Durbin told NBC the FBI and related agencies need more resources.

“We need to invest in the resources necessary for law enforcement,” said Durbin, who acknowledges the Boston attacks might be a call for a review of U.S. intelligence efforts.

Two bombs place Monday near the Boston Marathon finish line killed three people and injured more than 180 others.

McCaul identified the others in the terrorist category as Anwar al Awlaki, David Headley, Carlos Bledsoe and Nidal Hasan.

He said Faruq Abdulmutallab also attempted a terror attack despite being identified to the Central Intelligence Agency as a potential terrorist. The so-called “underwear bomber” attempted to blow up a U.S. airliner on Dec. 25, 2009.

Al Awlaki was an American-born Al Qaeda member killed in a 2011 U.S. drone attack in Yemen.  Headley is a Pakistani-American who pleaded guilty in 2010 to participating in terror attacks including the 2008 Mumbai, India, attacks that killed 164 people.

Bledsoe was born in Tennessee and converted to radical Islam before a 2009 attack on a military recruiting station in which he fatally shot an Army private.

Hasan, born in Virginia, is the Army officer accused of fatally shooting 13 people in 2009 at a military base in Fort Hood, Texas.