Five days after the US determined who was allegedly behind the deadly Boston marathon terror attacks, Washington is piecing together what happened and whether there were any unconnected dots buried in US government files that, if connected, could have prevented the bombings.
The surviving suspect, Dzhokhar Tsarnaev, 19, told authorities that his older brother, Tamerlan Tsarnaev, 26, only recently recruited him to be part of the attack, two US officials said Wednesday. The CIA, however, named Tamerlan to a huge, classified database of known and suspected terrorists 18 months ago, officials said, an acknowledgment that will undoubtedly prompt congressional inquiry about whether the Obama administration adequately investigated tips from Russia that Tsarnaev had posed a security threat.
Shortly after the bombings, US officials said the intelligence community had no information about threats to the marathon before the April 15 explosions.
The US officials who spoke to The Associated Press were close to the investigation but insisted on anonymity because they were not authorized to discuss the case with reporters.
Investigators have said the brothers, Russian-born ethnic Chechens, appeared to have been radicalized through jihadist materials on the Internet and have found no evidence tying them to a terrorist group.
Tamerlan, whom authorities have described as the driving force behind the plot, was killed in a shootout with police. Dzhokhar is recovering in a hospital from injuries sustained during a getaway attempt.
The CIA made the request to add Tamerlan's name to the terrorist database after the Russian government contacted the agency with concerns that he had become a follower of radical Islam. About six months earlier, the FBI had separately investigated Tsarnaev, also at Russia's request, but the FBI found no ties to terrorism, officials said.
Officials say they never found the type of derogatory information on Tsarnaev that would have elevated his profile among counterterrorism investigators and placed him on the terror watch list.
Lawmakers who were briefed by the FBI said they have more questions than answers about the investigation of Tsarnaev. US officials were expected to brief the Senate on the investigation Thursday.
Officials said Wednesday that Dzhokhar acknowledged to the FBI his role in the attacks but did so before he was advised of his constitutional rights to keep quiet and seek a lawyer.
It is unclear whether those statements would be admissible in a criminal trial and, if not, whether prosecutors even need them to win a conviction. Officials said physical evidence, including a 9 mm handgun and pieces of a remote-control device commonly used in toys, was recovered from the scene.
Authorities had previously said Dzhokhar exchanged gunfire with them for more than an hour Friday night before they captured him inside a boat covered by a tarp in a suburban Boston neighborhood backyard. But two US officials said Wednesday that he was unarmed when captured, raising questions about the gunfire and how he was injured.
Dzhokhar told the FBI that they were angry about the US wars in Afghanistan and Iraq and the killing of Muslims there, officials said.
How much of those conversations will end up in court is unclear. The FBI normally tells suspects they have the right to remain silent before questioning them so all their statements can be used against them.
Under pressure from Congress, however, the Department of Justice has said investigators may wait until they have gathered intelligence about other threats before reading those rights in terrorism cases. The American Civil Liberties Union has expressed concern about that.
Regardless, investigators have found pieces of remote-control equipment among the debris and were analyzing them, officials said. One official described the detonator as "close-controlled," meaning it had to be triggered within several blocks of the bombs.
They also recovered a 9 mm handgun believed to have been used by Tamerlan from the site of a Thursday night gunbattle that injured a Massachusetts Bay Transportation Authority officer, two US officials said.
The officials told the AP that no gun was found in the boat. Boston police Commissioner Ed Davis said earlier that shots were fired from inside the boat.
Asked whether the suspect had a gun in the boat, Davis said, "I'm not going to talk about that."
Dzhokhar's public defender had no comment on the matter Wednesday. His father has called him a "true angel," and an aunt has insisted he's not guilty.
The suspects' parents, Anzor Tsarnaev and Zubeidat Tsarnaeva, plan to fly to the US from Russia on Thursday, the father was quoted as telling the Russian state news agency RIA Novosti. The family has said it wants to take Tamerlan's body back to Russia.
In Russia, US investigators traveled to the predominantly Muslim province of Dagestan and were in contact with the brothers' parents, hoping to gain more information.
Investigators are looking into whether Tamerlan Tsarnaev, who spent six months in Russia's turbulent Caucasus region in 2012, was influenced by the religious extremists who have waged an insurgency against Russian forces in the area for years. The brothers have roots in Dagestan and neighboring Chechnya but had lived in the US for about a decade.
US officials described to the AP what the government knew about Tamerlan since he was first placed on the intelligence community's radar 18 months ago. The officials spoke on condition of anonymity because they were not authorized to publicly discuss the ongoing investigation.
Russia's internal security service, the FSB, sent information to the FBI about Tamerlan Tsarnaev on March 4, 2011. The Russians told the FBI that Tsarnaev was a follower of radical Islam and had changed drastically since 2010. Because of the subsequent FBI inquiry, Tsarnaev's name was added to a Homeland Security Department database used by US officials at the border to help screen people coming in and out of the US That database is called the Treasury Enforcement Communications System, or TECS.
The FBI's Boston office opened a preliminary review of Tsarnaev and searched government databases for potentially terror-related communications. Investigators looked into whether Tsarnaev used online sites that promoted radical activity. They interviewed Tsarnaev and his family members but found nothing connecting him to terror activity. The FBI shared that information with Russia and also asked for more information on Tsarnaev, but never heard back. The FBI's review into Tsarnaev was closed in June 2011.
Then, in late September 2011, Russia separately contacted the CIA with nearly identical concerns about Tsarnaev. The Russians provided two possible birthdates for him and a variation of how his name might be spelled, as well as the spelling in the Russian-style Cyrillic alphabet.
The CIA determined that Tsarnaev should be included in the Terrorist Identities Datamart Environment, known as TIDE, and the National Counterterrorism Center added it into the database. The spelling of Tsarnaev's name in TIDE was not the same as the spelling the FBI used in its investigation. The CIA also shared this information with other federal agencies in October.
In January 2012, Tsarnaev traveled to Russia and returned to the US in July. Three days before he left for Russia, the TECS database generated an alert on Tsarnaev. That alert was shared with a Customs and Border Protection officer who is a member of the FBI's Boston joint terrorism task force. By that time, the FBI's investigation into Tsarnaev had been closed for nearly six months because the FBI uncovered no evidence that he was tied to terror groups.
On Jan. 21, 2012, the airline on which Tsarnaev was traveling misspelled his name when it submitted its list of passengers to the US government for security screening. Airlines are required to provide the list of passengers on international flights so the US can check their names through government databases, including the terrorist watch list. Because his name was misspelled, there was not another alert like there was three days earlier.
In July 2012, Tsarnaev returned to the US, and another alert was generated in TECS. This information was again shared with the Customs and Border Protection officer on the FBI's Boston joint terrorism task force. But because the FBI had closed its investigation into Tsarnaev a year earlier, there was no reason to be suspicious of his travels to Russia.
"Later on, these agencies will be judged," said Congressman Dutch Ruppersberger, the top Democrat on the House of Representatives Intelligence Committee. "But right now, it's way too soon to criticize or to start making political arguments or who failed or whatever."