As the investigation into the Boston Marathon bombing continued Sunday, family members prepared to bury the victims, and hundreds of stunned and sorrowful residents prayed together for the dead and wounded and worked to reclaim the streets where the violence occurred a week ago.

Federal officials had yet to file charges against 19-year-old Dzhokhar Tsarnaev, who was captured Friday and remains in serious condition under heavy guard at Boston's Beth Israel Deaconess Medical Center. He was shot in the neck and, at least for a while, was intubated, making it impossible for him to speak with agents.

Tsarnaev and his 26-year-old brother, Tamerlan, who was killed during the massive manhunt, are the only suspects in the bombing at the marathon's finish line, which killed three, wounded 170 and paralyzed this major metropolitan region.

Fifty-two bombing victims remained hospitalized Sunday, 17 of them in critical condition, officials said. A transit police officer shot and wounded in pursuit of the suspects had to be resuscitated after his heart stopped and he lost all of his blood, but doctors and relatives on Sunday said he was emerging from sedation and was expected to recover.

The Tsarnaev brothers are ethnic Chechens who came to the United States seeking refugee status with their family about a decade ago. Questions continued to swirl about the young men's motives, whether they acted alone, whether they were planning more attacks and whether the FBI did enough to investigate the older brother after he was flagged as a possible Islamic radical.

Tamerlan called his mother Thursday morning, just hours before his death in a shootout with police, and told her he had received a call from the FBI, she said.

"He would call me every day from America in the last days," Zubeidat Tsarnaev said Sunday in a telephone interview with the Los Angeles Times from her home in the Russian republic of Dagestan. "During our last conversation on the morning (before the shootout), he was especially touching and tender and alarmed at the same time."

Her son, she said, told her that he "got a private phone call" from the FBI. Agents told him that he was "under suspicion and should come see them."

" 'If you need me, you will find me,' he said, and hung up," she recounted, beginning to sob. "You know the FBI followed him for several years, and, when he got back from Dagestan last year, they called him and asked him what was the purpose of his visit to his homeland."

The FBI has acknowledged that it interviewed Tamerlan in early 2011 after a foreign government, which law enforcement officials say was Russia, raised concerns about whether he had ties to extremist organizations.

The Republican chairman of the House Intelligence Committee said Sunday that the FBI did "a very thorough job" vetting Tamerlan Tsarnaev after questions were raised about his possible ties to radical Islamists.

Rep. Mike Rogers, R-Mich., a former FBI agent who has not hesitated to criticize the bureau and Obama administration on counterterrorism issues, said on NBC's "Meet the Press" that the FBI examined Tsarnaev's "digital footprints," conducted all the database checks at its disposal and interviewed him. Rogers said that no evidence emerged to justify further scrutiny.

Brad Garrett, a former FBI agent, said on ABC's "This Week" that merely visiting extremist websites would not merit an FBI investigation. "There are hundreds of thousands of young adults in this country that visit extremist Islamic websites," he said. "So the question is what line you draw."

And Defense Secretary Chuck Hagel, on a plane from Washington to Tel Aviv Sunday morning, told reporters that he had seen no evidence of links between the Tsarnaev brothers and organized terrorist organizations, although he emphasized that the investigation was continuing.

Reports have circulated that Tamerlan Tsarnaev may have been angry because his citizenship application was denied, but a law enforcement official said Sunday that it was still under review at the time of his death.

Tsarnaev applied for citizenship about six months ago, the official said, and U.S. Citizenship and Immigration Services was aware he had been charged with domestic violence against a girlfriend and was interviewed by the FBI in 2011. It's unclear what Tsarnaev was told about his prospects for citizenship.

The older brother was a permanent resident and held a Russian passport. His younger brother became a U.S. citizen on Sept. 11, 2012.

Government and law enforcement officials in Massachusetts painted a picture of the brothers Sunday as coldblooded and methodical.

Massachusetts Gov. Deval Patrick said surveillance video from the explosion scene shows Dzhokhar Tsarnaev setting his backpack down at the finish line, waiting for the first bomb to go off and then moving away from the satchel before the second explosion.

Patrick, who has been briefed on the tapes but has not seen them, said the video puts 19-year-old Tsarnaev at the scene of the attack.

"It does seem to be pretty clear that this suspect took the backpack off, put it down, did not react when the first explosion went off and then moved away from the backpack in time for the second explosion," Patrick said on "Meet the Press." "It's pretty clear about his involvement and pretty chilling, frankly."

Boston Police Commissioner Ed Davis said that he believed the Tsarnaevs were planning additional attacks, a conclusion he drew from the weapons and homemade bombs recovered after the brothers engaged in a shootout Friday with police in Watertown, Mass., a suburb of Boston. The young men were not licensed to own firearms.

"We have reason to believe, based upon the evidence that was found at that scene - the explosions, the explosive ordinance that was unexploded and the firepower that they had - that they were going to attack other individuals," Davis said on CBS' "Face the Nation."

But their precision only went so far.

About five hours after federal investigators published the pair's photos Thursday, police said, they killed a Massachusetts Institute of Technology police officer near the campus and carjacked a Mercedes SUV.

The Mercedes driver escaped, Cambridge police told the Times, after the brothers went into a Shell gas station to buy snacks.

The very site that police say the Tsarnaevs targeted for tragedy became a sacred spot Sunday afternoon, as worshipers from a variety of faiths gathered close to the Boston Marathon finish line to pray, sing and "reconsecrate" what is still an active crime scene.

They warbled patriotic songs such as "America the Beautiful" and a hymn that begins "Guide my feet while I run this race." Rabbi Howard Berman of Central Reform Temple opened with a prayer to reclaim streets that are still closed to cars and pedestrians.

After the brief service, people edged toward the memorial at the race's finish line, which has been blanketed with flowers, stuffed animals, flags and balloons. Three crosses stood with the names and photos of the three people who died in the attack: Martin Richard, Krystle Campbell and Lu Lingzi.

The family of 8-year-old Martin has yet to solidify plans for the boy's funeral. A memorial service for Lu will be held Monday at Boston University, where she was a graduate student. Campbell will be buried Monday in nearby Medford.


(Memoli and Mason reported from Boston and Loiko from Moscow. Staff writers Ken Dilanian, Shashank Bengali, Brian Bennett and Richard A. Serrano in Washington, Molly Hennessy-Fiske, Michael J. Mishak, Ashley Powers and Maria L. La Ganga in Boston and Matt Pearce in Los Angeles contributed to this report.)


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