The unanswered questions include, beyond the location of the suspected bomber, any idea of motive or explanation for how the two brothers came to be possible murderers.
“Somebody radicalized them,” the brothers' uncle, Ruslan Tsarni, told reporters outside his suburban Maryland home late Friday morning.
In one hint of potential radical interests, a profile published under Dzhokhar Tsarnaev's name on a Russian-language social media site resembling Facebook had links to news videos about terrorist attacks on the subways in Moscow and in the Belarus capital of Minsk.
The violent odyssey that began Monday resumed Thursday evening just a few hours after the FBI released photos and videos of suspects in the Boston Marathon bombings, when a security camera in a convenience store in Cambridge captured an image of one of the men.
At 10:30 p.m., Massachusetts Institute of Technology police officer Sean Collier, 26, of Somerville, Mass., was found fatally shot in his cruiser. He was rushed to Massachusetts General Hospital, where he was pronounced dead.
The two suspects then carjacked a Mercedes SUV at gunpoint, reportedly identifying themselves to the car's owner as the perpetrators of the marathon bombing. The car's owner escaped half an hour later at a gas station and the SUV headed toward Watertown, about eight miles from downtown Boston. Police chased the suspects, even as they tossed several explosive devices at officers from their car.
About 12:45 a.m., gunfire broke out between the suspects and police in Watertown. Massachusetts Bay Transit Authority Police Officer Richard H. Donohue was badly wounded in the shootout, in which officials said some 200 shots were fired. Tamerlan Tsarnaev also suffered serious injuries and was pronounced dead at Beth Israel Deaconess Medical Center at 1:35 a.m. His younger brother got away in the car, setting off a chase that led to close police scrutiny of area.“We are progressing through this neighborhood,” Alben told reporters at about noon Friday. “We are going house by house, street by street.”
Officials revealed that a resident alerted the Watertown Police Department to the potential hiding site late Friday. The neighborhood had been locked down all day, but law enforcement officials advised residents after 6 p.m. that it was safe to go outside. One Franklin Street resident went to check on his boat.
“He happened to notice that the boat didn't look right, so he looked inside. That's where he saw the blood and the body,” Franklin Street resident George Pizzuto told ABC.
The uncle, Ruslan Tsarni, told reporters that the brothers were ethnic Chechens, though they were not born in Chechnya. The younger brother was born in Kyrgyzstan, Tsarni said. The suspects' aunt, Maret Tsarnaev, said on Canadian television that the father worked as a lawyer and in an “enforcement” agency in his home country, which she said eventually put him at risk.
“He is a soft-hearted, loving father,” the aunt said.
The aunt said she was living in the United States in April 2002 when Dzhokhar arrived along with his mother and father, while the other brother and two sisters remained with relatives in Kazakhstan. The family petitioned for refugee status; the father and mother are now living in the capital city of the Russian republic of Dagestan, where the father, Anzor, told television reporters Friday that he suspected his sons may have been set up as fall guys for what he denounced as a heinous attack in Boston.
“I honestly can't imagine who could do this,” the father told a Dagestan TV station. “Whoever did this is a bastard.”
The family has been disrupted in recent years, and interviews, social media and public records suggest they weren't close. Tsarni told reporters he had little contact with his brother's family, but he would not elaborate on why. A sister of the two suspects, interviewed by the FBI in suburban New Jersey, told reporters through a crack in her door that she had not been in frequent touch with her brothers.
“I never imagined that the children of my brother would be associated with that (bombing),” the uncle said, adding that they “put a shame on our family, (they) put a shame on the entire Chechen ethnicity.”
Chechnya President Ramzan Kadyrov, in a Russian-language Internet posting translated by McClatchy, vigorously distanced his war-torn country from the two suspects.
“It would be useless to try to make any connection between Chechnya and these Tsarnaevs, if they are indeed guilty,” the president wrote. “They grew up in the United States; their attitudes and beliefs were formed there. The roots of this evil must be sought in America.”
Christopher Swift, adjunct professor of national security studies at Georgetown University, further pointed out that there are big cultural and language differences between Arab and Chechen Muslims.
“They are totally different cultures,” Swift said. “It's like Greek people going to Ireland. . There's a big difference between Irish Catholicism and Greek Orthodox Christianity as practiced in Greece.”
The older brother, Tamerlan, was studying at Bunker Hill Community College and had been a boxer. He was married.
The younger brother, Dzhokhar, was a naturalized U.S. citizen who came to the United States in 2002 and attained his citizenship on Sept. 11, 2012. Known by friends and family members as Jahar, he was a student and wrestler at the Dartmouth satellite campus of the state university.