Une impressionnante chasse à l'homme était en cours vendredi près de Boston entièrement bouclée, pour retrouver un jeune de 19 ans d'origine tchétchène, soupçonné avec son frère, tué dans la nuit, des attentats meurtriers de lundi.

La population de Boston et sa banlieue - environ un million de personnes- , a passé la journée enfermée chez elle, sur ordre des autorités. Tous les transports en commun étaient arrêtés, magasins et écoles fermés, tout survol d'avion interdit. Les trains ne circulaient pas entre New York et Boston.

Des centaines de policiers casqués, en tenue de combat, certains postés sur les toits, ont vérifié, maison après maison les rues de Watertown, dans la banlieue ouest de Boston, où s'était déroulée dans la nuit la traque des deux frères, dans une spectaculaire accélération de l'enquête.

Ces derniers ont été identifiés comme Tamerlan Tsarnaev, 26 ans, pour celui tué dans la nuit, et Djokhar Tsarnaev, 19 ans pour le plus jeune toujours recherché.

D'origine tchétchène, les frères avaient immigré en 2003 aux Etats-Unis, a déclaré vendredi un oncle, Ruslan Tsarni, se disant "honteux" à l'idée qu'ils puissent avoir été impliqués dans les attentats qui ont fait trois morts et près de 180 blessés lundi à Boston.

Et il a lancé un appel à son plus jeune neveu, lui demandant de se "rendre et demander pardon", s'il était encore vivant.

Le secrétaire d'Etat américain John Kerry s'est refusé à "spéculer" sur le lien que pourrait avoir l'attentat avec les origines tchétchènes des deux suspects, qui vivaient enfants au Kirghizstan.

Le président de Tchétchénie, république du Caucase russe majoritairement musulmane, a lui souligné que les suspects n'avaient "pas vécu en Tchétchénie". "Ils ont vécu et étudié aux Etats-Unis (...) Ils ont forgé leurs opinions et convictions là-bas. Il faut trouver les racines du mal en Amérique", a-t-il ajouté, cité par l'agence publique de presse Ria Novosti.

Les deux frères vivaient depuis des années à Cambridge, en banlieue de Boston.

Un homme se présentant comme leur père les a décrits comme "des musulmans fervents", depuis la capitale du Daguestan, Makhatchkala.

L'aîné, ex-étudiant ingénieur devenu boxeur, avait une page Youtube à son nom, créée en août 2012, où il avait marqué plusieurs vidéos comme favorites dans les catégories "islam" et "terrorisme".

Le plus jeune, qui faisait de la lutte, était inscrit dans une université de la région.

L'aîné était l'homme que des images publiées jeudi par le FBI montraient sur le lieu des attentats lundi dernier, avec une casquette noire et un sac à dos noir. Le plus jeune figurait sur les mêmes images, portant une casquette claire visière à l'arrière, et un sac à dos sur l'épaule.

La police de Boston a publié vendredi une nouvelle photo de Djokhar, montrant un adolescent aux yeux bruns et à la chevelure indisciplinée.

Les deux hommes sont soupçonnés d'avoir déposé les deux bombes artisanales qui ont explosé près de la ligne d'arrivée du marathon lundi en plein centre de Boston.

L'attentat non revendiqué a traumatisé la ville et ravivé aux Etats-Unis le souvenir du 11-Septembre.

Un policier tué, un autre grièvement blessé

Le chef de la police de Boston Ed Davis a souligné que Djokhar Tsarnaev était considéré comme très dangereux.

"Nous pensons que c'est un terroriste. Nous pensons que c'est un homme qui est venu ici pour tuer des gens" a-t-il déclaré, après la traque des deux frères durant la nuit, marquée par des échanges de coups de feu nourris et la mort d'un policier de 26 ans, tué par les deux hommes dans sa voiture.

La police continuait vendredi à s'interroger sur la possibilité qu'ils n'aient pas agi seuls. La question du motif reste entière.

"La situation évolue rapidement", a déclaré vendredi le gouverneur Deval Patrick vendredi. Le chef de la police du Massachusetts Tim Alba a fait état de "plusieurs nouvelles pistes", sans élucider.

La traque des deux frères avait commencé dans la nuit à Cambridge, sur le campus du Massachusetts Institute of Technology (MIT) à l'ouest de Boston.

La police, alertée après des coups de feu découvre un policier tué par balles dans sa voiture à 22H30, et la police apprend ensuite que les deux fuyards ont détourné une voiture en menaçant d'une arme son conducteur. Celui ci sera libéré sain et sauf 30 minutes plus tard.

Les deux frères lui auraient confié être les auteurs des attentats.

La chasse à l'homme commence, alors qu'ils roulent à pleine vitesse en direction de Watertown, située encore plus à l'ouest de Boston.

S'ensuivent des échanges de coups de feu nourri, durant lequel un policier est grièvement blessé.

C'est durant cette poursuite que l'aîné, sorti de la voiture, est mortellement blessé. Il est déclaré mort à l'hôpital à 1H25 (5H25 GMT) tandis que son frère prend la fuite en voiture.

Cette accélération spectaculaire dans l'enquête est intervenue moins de 12 heures après que le FBI eut diffusé des images des deux hommes et lancé un appel au public, pour qu'il l'aide à les identifier.

Les deux bombes ayant endeuillé le célèbre marathon avaient explosé à 100 mètres de distance, et 12 secondes d'intervalle, près de la ligne d'arrivée, alors que des dizaines de milliers de personnes étaient massées au centre de Boston pour ce qui est chaque année une grande fête populaire.

Elles avaient été assemblées dans des cocottes-minute remplies de clous et de billes d'acier pour en maximiser les dégâts.

LIRE AUSSI:
» Les deux suspects Tamerlan et Djokhar Tsarnaev ont grandi au Kirghizstan, selon leur oncle
» Qui sont les frères Tsarnaev, les suspects de l'attentat de Boston
» Attentat du marathon de Boston: un suspect mort, l'autre en cavale à Watertown
» "Heartbreak Hill", le roman qui avait prédit l'attentat
» Des noms de sites internet achetés pour éviter de voir fleurir les théories du complot
» Témoignage poignant d'une spectatrice du Marathon de Boston
» Martin, 8 ans, venait d'enlacer son papa à l'arrivée quand la bombe l'a tué
» Bombes de Boston: des cocottes-minute, des billes et des clous

Cette vidéo diffusée sur YouTube montrerait la fusillade ayant entraîné la mort d'un suspect

Loading Slideshow...
  • Police Search For Suspect

    A police officer with gun drawn searches for a suspect on April 19, 2013 in Watertown, Massachusetts. Earlier, a Massachusetts Institute of Technology campus police officer was shot and killed late Thursday night at the school's campus in Cambridge. A short time later, police reported exchanging gunfire with alleged carjackers in Watertown, a city near Cambridge. It's not clear whether the shootings are related or whether either are related to the Boston Marathon bombing.

  • Man Taken Into Custody

    Man being taken into custody on Nichols Ave and Quimby. Police overheard saying "he has shit all in his pockets."

  • Cops In Bullet Proof Vests

    Cops suiting up with bullet proof vests in Watertown.

  • Reports Of Shooting, Explosions In Watertown

    A vehicle carrying officers in tactical gear arrives at the Watertown neighborhood of Boston, Friday, April 19, 2013. Dozens of officers and National Guard members are in Watertown, where television outlets report that gunfire and explosions have been heard.

  • Officers Arrive In Watertown

    Officers wearing tactical gear arrive at the Watertown neighborhood of Boston, Friday, April 19, 2013.

  • FBI On Scene In Watertown

    An FBI official arrives at the Watertown neighborhood of Boston, Friday, April 19, 2013.

  • Raw Shooting at MIT Watertown

    A NewsCenter 5 viewer sent in uncut video of a shootout between police and at least one suspect in the streets of Watertown, Mass.

  • Police Establishing Perimeter

    Boston Police are setting up perimeter tape across Nichols Avenue right now.

  • Confrontation In Watertown

    Boston Police chief on the scene in Boston's Watertown neighborhood.

  • Christina Wilkie Reports From Watertown

  • FBI Agents Arrive In Watertown

    A half-dozen FBI agents just arrived at the Nichols Ave perimeter. At least one in a bulletproof vest.

  • Michael McLaughlin Reports From Watertown

  • Christina Wilkie Reports From Watertown

  • Police Surround Apartment In Watertown

    A heavily armored bearcat turns onto Quimby Street, headed towards the apartment.

  • Police Search For Suspect

    Police with guns drawn search for a suspect on April 19, 2013 in Watertown, Massachusetts.



UN BLOGUE EN DIRECT DE NOS COLLÈGUES AMÉRICAINS:

The Washington Post has published a long account of investigators' exhaustive efforts to find the Boston Marathon suspects using mountains of video footage and photographs, as well as other leads. An excerpt:

Quickly, the authorities secured a warehouse in Boston’s Seaport district and filled the sprawling space: On half of the vast floor, hundreds of pieces of bloody clothes were laid out to dry so they could be examined for forensic clues or flown to FBI labs at Quantico in Prince William County for testing. In the other half of the room, more than a dozen investigators sifted through hundreds of hours of video, looking for people “doing things that are different from what everybody else is doing,” Boston Police Commissioner Edward Davis said in an interview Saturday. The work was painstaking and mind-numbing: One agent watched the same segment of video 400 times.

Read the whole thing here.

Partager:

CBS News reports that Boston bombing suspect captured on Friday night suffered at least two bullet wounds, and that one of them may be evidence that he tried to end his own life.

The bullet wound to the neck, which has an exit wound in the back of the 19-year-old’s neck, “is very possibly a suicide attempt,” said Miller, a former assistant director at the Federal Bureau of Investigation.

Read the whole report here.

Partager:

The Daily News reports:

The two men, known to neighbors by their first names Azmat and Diaz — who share a black BMW SUV adorned with a novelty license plate that reads “Terrorista #1” — were cuffed and hauled out of their Carriage Dr. apartment shortly before 4 p.m.

The apparent arrests occurred about 30-45 minutes after authorities with the FBI, ICE and the U.S. Department of Homeland Security descended on the Hidden Brook Apartment complex.

Read more here.

Partager:

The Guardian has an account of the dead bombing suspect's 2012 voyage to Dagestan, a small, troubled region of Russia where he had once lived:

According to US travel records, Tsarnaev arrived at Moscow's Sheremetyevo airport on 12 January, returning on 17 July. He spent time in Makhachkala that summer. "It was 40C and he was wearing these American boots," said Larissa Abakarova, who maintains a shop across the street from the home of the parents of Tsarnaev and his brother, Dzhokhar, who was arrested late on Friday. "He was stylish, kind, good-looking. I'm in shock."

Read the whole thing here.

Partager:

The Washington Post has a new story that fills in many details of the Tsarnaev brothers' bloody path to Watertown, including their murder of an MIT Cop:

Just after 10:30 p.m. Thursday, the pair walked up to a parked police car at the Massachusetts Institute of Technology, where Sean Collier, a 26-year-old campus officer, was nearing the end of his 3-to-11 p.m. shift.

A security camera would later show two men approaching the car and speaking to the officer. Abruptly, one of the men was seen pulling a gun and shooting Collier multiple times, including once in the head. Some officers concluded that the shooting was an effort to provoke a larger confrontation with police.

“They were looking to start something,” one official said.

Read the whole thing here.

Partager:

From the AP:

Ruslan Tsarni says he grew concerned about Tamerlan Tsarnaev (tsahr-NEYE'-ehv) when he told him in a 2009 phone conversation that he had chosen "God's business" over work or school. Tsarni said he then contacted a family friend who told him Tsarnaev had been influenced by a recent convert to Islam.

Partager:

A doctor involved in treating the Boston Marathon bombing suspect who died in a gunbattle with police says he had injuries head to toe and all limbs intact when he arrived at the hospital.

Dr. David Schoenfeld said 26-year-old Tamerlan Tsarnaev was unconscious and had so many penetrating wounds when he arrived at Beth Israel Deaconess Medical Center early Friday that it isn't clear which ones killed him, and a medical examiner will have to determine the cause of death.

READ MORE

Partager:

Read more here.

Partager:

The New York Times reports that the decision to release the photos of the marathon bombing suspects to the public was a major turning point in the investigation.

The authorities knew that broadly distributing the images — some captured by ubiquitous surveillance cameras and cellphone snapshots and winnowed down using sophisticated facial-recognition software — would accelerate the digital dragnet, but they did not realize the level of chaos it would create.

Intelligence and law enforcement officials said the authorities in Boston weighed the risks of some mayhem against their growing fear that time was slipping away and that heavily armed and increasingly dangerous men, and possibly accomplices, could wage new attacks in the Boston area or beyond.

Read the rest here.

Partager:

Syracuse University Professor Anthony Rotolo and student Andrew Bauer mapped 200 of the tweets sent out from Boston in the hours right after the marathon bombing, creating an interactive portrait of the city's reaction to Monday's horrifying events.

See the map here.

(h/t Mashable)

Partager:

His actions may have been vital in helping police catch the Boston Marathon bombing suspects, even after the attacks both his legs were amputated from the knee down. Now some of that heroism is being returned.

Nearly 10,000 people have now donated to Bucks for Bauman, an effort to help pay the medical expenses of Jeff Bauman, the Boston Marathon bombing survivor known not only for a now iconic -- and extremely graphic -- photo, but also for helping the FBI identify at least one of the bombing suspects. Set up by his friends on the crowdfunding site GoFundMe, the fund has already raised more than $360,000 since last Tuesday to help pay for Bauman’s devastating injuries.

READ MORE

Partager:

Massachusetts Gov. Deval Patrick says the surviving suspect in the Boston Marathon bombings is in serious but stable condition and likely can't communicate yet.

Patrick spoke outside Fenway Park after appearing in a pregame ceremony at Saturday afternoon's Red Sox game.

READ MORE

Partager:

The American Civil Liberties Union says it's concerned the surviving Boston Marathon bombing suspect will be questioned by investigators without being read his Miranda rights.

READ MORE

Partager:

Details of the manhunt for the Boston Marathon bombing suspects were murky at the height of the investigation, leading many news outlets to misreport the facts. But now that both suspects have been apprehended, the specific circumstances of the search that locked down one Boston suburb for nearly 18 hours are becoming more clear.

READ MORE

Partager:

Federal public defenders have agreed to represent the suspect in the Boston Marathon bombings.

Miriam Conrad, the federal defender for Massachusetts, says her office expects to represent Dzhokhar Tsarnaev after he is charged.

READ MORE

Partager:

boat

How police saw that someone was in the boat without removing the tarp covering it.

Image credit: Massachusetts State Police

Partager:

Republican lawmakers issued a statement Saturday urging President Barack Obama to treat Dzhokhar Tsarnaev, the suspect in the Boston Marathon bombings, as an "enemy combatant."

Sens. Lindsey Graham (R-S.C.), John McCain (R-Ariz.) and Kelly Ayotte (R-N.H.) and Rep. Peter King (R-N.Y.) said Tsarnaev "clearly is a good candidate for enemy combatant status" in a statement posted to Graham's website.

"We do not want this suspect to remain silent," the lawmakers said in their statement.

READ MORE

Partager:

Wearing special home jerseys with "Boston" sewn across the chest, the Red Sox returned to Fenway Park on Saturday afternoon. More importantly, the people of Boston gathered together to resume their normals lives and root, root, root for the home team just one day after authorities aprehended the second suspect in the Boston Marathon bombings.

The Red Sox game against the Kansas City Royals was preceded by an emotional pre-game ceremony that honored the victims of the horrific attacks on the Boston Marathon and paid tribute to law enforcement officials, first responders, race participants and volunteers. The emotional scene also included a stirring montage of images from the tumultuous week in Boston set to the song "Hallelujah" as performed by Jeff Buckley, ceremonial first pitches and yet another rousing sing-along rendition of the national anthem.

READ MORE

Partager:

One of the two ethnic Chechens suspected by U.S. officials of being behind the Boston Marathon bombings had been under FBI surveillance for at least three years, his mother said.

Zubeidat Tsarnaeva told the English-language Russia Today state television station in a phone interview, a recording of which was obtained by Reuters, that she believed her sons were innocent and had been framed.

Tamerlan Tsarnaev, 26, was killed in a shootout with police and his 19-year-old brother Dzhokhar was captured after a day-long manhunt.

READ MORE

Partager:

College students in Boston were dancing in the streets Friday night after a week of turmoil.

The fatal bombings at the Boston Marathon on Monday locked down many higher education institutions in the Boston metro area, forcing them to cancel classes.

Just as colleges began to recover from the attack, a Thursday night shooting on the Massachusetts Institute of Technology campus left one officer dead. One of the bombing suspects was killed in a shoot-out with police a short time later, and a subsequent manhunt for remaining bombing suspect Dzhokhar Tsarnaev put schools back on lockdown Friday.

READ MORE

Partager:
Handguns, a rifle and at least six bombs -- three of which exploded -- were found at the scene early Friday after officers first confronted the two Boston Marathon bombing suspects in the darkness of a residential street, the Watertown, Massachusetts, police chief told

CNN's Wolf Blitzer on Saturday.

A single officer was the first to encounter the two cars that Tamerlan and Dzhokar Tsarnaev were driving, just before 1 a.m. Friday, Chief

Edward Deveau said.

Read more at CNN

Partager:

David Henneberry may not have tried to be a hero, but that's what he's being called.

The Watertown boat owner was the first to spot the bombing suspect Dzhokhar Tsarnaev after the 19-year-old eluded police following a shootout early Friday.

Henneberry tipped off police, leading to the eventual capture of Tsarnaev Friday night.

READ MORE

Partager:

President Barack Obama spoke about the "resolve and resilience" of Boston during his weekly address on April 20.

"On Monday, an act of terror wounded dozens and killed three innocent people at the Boston Marathon," Obama says in a video posted to the White House's YouTube page on Saturday. "But in the days since, the world has witnessed one sure and steadfast truth: Americans refuse to be terrorized."

READ MORE

Partager:

If you found in your copy of Friday morning's New York Post a letter from the paper's editor-in-chief, Col Allan, expressing "regret" over the Post's "intentionally misleading and harmful" coverage of the Boston bombing, you might have thought, well, that's appropriate, but I didn't see that coming given the fact that Allan wasn't apologetic yesterday, for his paper's astounding failures during this trying week.

Also, you may have gone on to think, this letter is unusually eloquent for a man who essentially has nothing but cheap gin and trash pulled from the East River sloshing around inside his skull.

Well, allow me to penetrate the mystery.

READ MORE

Partager:
Partager:

New York state Sen. Greg Ball (R) suggested using torture on Dzhokhar Tsarnaev, the suspect in the Boston Marathon bombing, in a tweet Friday night.

Tsarnaev was captured by authorities late Friday evening in Watertown, Mass., four days after the Boston Marathon bombing. Authorities say the suspect and his brother, 26-year-old Tamerlan Tsarnaev, killed an MIT police officer, severely wounded another lawman and hurled explosives at police in a car chase and gun battle.

READ MORE

Partager:

President Barack Obama Friday night praised law enforcers and Bostonians after the massive manhunt that led to the capture of the second suspect in the Boston Marathon bombings. The first suspect was killed Thursday in a shootout with police.

As he began his address, Obama thanked the public, saying, "Tonight, our nation is in debt to the people of Boston." He went on to thank Bostonians as "citizens and partners" in the investigation.

The president said he had ordered the "full resources of the federal government" to help in the investigation that he said wouldn't have been possible without close coordination among federal, state and local authorities.

"They all worked as they should," Obama said, "as a team."

Read more here.

Partager:

HuffPost's Michael McLaughlin and Christina Wilkie report:

WATERTOWN, Mass. -- Friday morning in the Boston area began in a tense silence, as the sprawling manhunt for an alleged teenaged terrorist forced city residents indoors for their own safety. Friday night, however, ended with spontaneous parades celebrating his capture.

As 19-year-old Dzhokhar Tsarnaev was pulled wounded from his backyard boat hideout and raced to Beth Israel Hospital in police custody, many Bostonians finally exhaled, after a devastating week that began with the double bombings at Monday’s Boston marathon. The suspect's brother, Tamerlan Tsarnaev, 26, was killed Friday morning in a shootout with police.

"CAPTURED!!!" trumpeted the Boston Police Department on Twitter Friday night. "The hunt is over. The search is done. The terror is over. And justice has won. Suspect in custody."

Read more here.

Partager:

Partager:

Message from FBI Director Robert S. Mueller:

During this long week, we have seen an extraordinary effort by law enforcement, intelligence, and public safety agencies. These collaborative efforts, with the help and cooperation of the public, resulted in the successful outcome we have seen tonight. The investigation will continue as part of our efforts to seek answers and justice, and there will be no pause in that effort. But tonight, I wish to thank all those who worked so tirelessly throughout the week in the pursuit of safety and justice.

Partager:

AVERTISSEMENT: LES PHOTOS CI-DESSOUS PEUVENT CHOQUER CERTAINES PERSONNES.

Loading Slideshow...
  • Boston Marathon Explosion

    Police officers with their guns drawn hear the second explosion down the street. The first explosion knocked down a runner at the finish line of the 117th Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    Newspapers are on sale at a stand on Newbury Street on April 16, 2013 in Boston, Massachusetts. Security is especially tight in the city of Boston after two explosions went off near the finish of the Marathon, killing three people and injuring at least 141 others. Darren McCollester / Getty Images)

  • WARNING

    Some photos in this slideshow are graphic and may be disturbing to some viewers.

  • Boston Marathon Explosion

    In this photo provided by The Daily Free Press and Kenshin Okubo, people react to an explosion at the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (Kenshin Okubo / The Daily Free Press / AP)

  • Boston Marathon Explosion

  • Boston Marathon Explosion

    A woman kneels and prays at the scene of the first explosion on Boylston Street near the finish line of the 117th Boston Marathon on April 15, 2013. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    Victims are in shock and being treated at the scene of the first explosion that went off near the finish line of the Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    People tend to an injured woman on the corner of Exeter and Newbury Streets after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Bill Greene / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    Bystanders help an injured woman at the scene of the first explosion on Boylston Street near the finish line of the 117th Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    Medical workers runs an injured man past the finish line the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (Charles Krupa / AP)

  • Boston Marathon Explosion

    Police and federal officials exit an apartment complex at 364 Ocean Avenue with a possible connection to the earlier expolsions during the Boston Marathon on April 15, 2013 in Revere, Massachusetts. Three people are confirmed dead and at least 141 injured after two explosions went off near the finish line to the marathon. (Darren McCollester / Getty Images)

  • Boston Marathon Explosion

    A victim of the first explosion is helped on the sidewalk of Boylston Street, after two explosions went off near the finish line of the 117th Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    Unclaimed finish line bags are viewed near the scene of a twin bombing at the Boston Marathon, on April 16, 2013 in Boston, Massachusetts. Three people are confirmed dead and at least 141 injured after the explosions went off near the finish line of the marathon yesterday. The bombings at the 116-year-old Boston race, resulted in heightened security across the nation with cancellations of many professional sporting events as authorities search for a motive to the violence. (Spencer Platt / Getty Images)

  • Boston Marathon Explosion

    A heavily armed Boston police officer (R) and a National Guard soldier (L) stands guard in front of the Taj Hotel April 16, 2013 in Boston, Massachusetts, in the aftermath of two explosions that struck near the finish line of the Boston Marathon April 15. A massive probe was underway Tuesday after two bombs struck the Boston Marathon, killing at least three and wounding more than 100. Monday's blasts near the finishing line raised fears of a terrorist attack more than a decade after nearly 3,000 people were killed in suicide airliner strikes on New York, Washington and Pennsylvania on September 11, 2001. US President Barack Obama went on national television to warn against "jumping to conclusions" but a senior White House official, speaking on condition of anonymity, said such an attack was "clearly an act of terror." (Stan Honda / AFP / Getty Images)

  • Boston Marathon Explosion

    A man comforts a victim on the sidewalk at the scene of the first explosion near the finish line of the 117th Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images

  • Boston Marathon Explosion

    Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (David L. Ryan / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    Boston Police look at blown out windows at the scene of the first explosion on Boylston Street near the finish line of the Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: Police officers with their guns drawn hear the second explosion down the street. The first explosion knocked down a runner at the finish line of the 117th Boston Marathon. (Photo by John Tlumacki/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

  • Boston Marathon Explosion

    Injured people lie on the sidewalk near a barrier at the scene of the first explosion that went off near the finish line of the 117th Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

    Passersby put pressure on a victim's leg to try to stop the bleeding at the scene of the first explosion near the finish line of the Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    The marathon finish line bridge is seen on Boylston Street on April 16, 2013 in Boston, Massachusetts. on April 16, 2013 in Boston, Massachusetts. Security is especially tight in the city of Boston after two explosions went off near the finish of the Marathon, killing three people and injuring at least 141 others. (Darren McCollester / Getty Images)

  • Boston Marathon Explosion

    Blood from victims covers the sidewalk on Boylston Street, at the site of an explosion during the 2013 Boston Marathon in Boston, Monday, April 15, 2013. At the right foreground is a folding chair with the design of an American flag on the cover. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (Charles Krupa / AP)

  • Boston Marathon Explosion

    A runner reacts near Kenmore Square after two bombs exploded during the 117th Boston Marathon on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 23 injured after two explosions went off near the finish line to the marathon. (Alex Trautwig / Getty Images)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene in a wheelchair. (Photo by David L. Ryan/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

    A runner passes a police officer dressed in tactical gear, who blocks a road leading to the Boston Marathon route, the morning after explosions killed three and injured more than 140 in Boston, Tuesday, April 16, 2013. The bombs that blew up seconds apart at the finish line of one of the world's most storied races left the streets spattered with blood and glass, and gaping questions of who chose to attack at the Boston Marathon and why. (Charles Krupa / AP)

  • Boston Marathon Explosion

    A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene in a wheelchair. (David L. Ryan / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    Carlos Arredondo, who was at the finish line of the 117th Boston Marathon when two explosives detonated, leaves the scene on April 15, 2013 in Boston, Massachusetts. Two people are confirmed dead and at least 28 injured after at least two explosions went off near the finish line to the marathon. (Darren McCollester / Getty Images)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene on a stretcher. (Photo by David L. Ryan/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

    Officials react as the first explosion goes off on Boylston Street near the finish line of the 117th Boston Marathon on April 15, 2013. (John Tlumacki / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    First responders tend to the wounded after two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. (Kelvin Ma / Bloomberg / Getty Images)

  • Boston Marathon Explosion

    Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: Two officials run away from the first explosion, right, on Boylston Street at the 177th Boston Marathon, April 15, 2013. (Photo by John Tlumacki/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

    A person who was injured in the first explosion is wheeled across the finish line of the Boston Marathon. (John Tlumacki / The Boston Globe / Getty Images)

  • Explosions At 117th Boston Marathon

    BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene on a stretcher. (Photo by David L. Ryan/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

  • Boston Marathon Explosion

    Neighbors hug outside the home of the Richard family in the Dorchester neighborhood of Boston, Tuesday, April 16, 2013. Martin Richard, 8, was killed in Mondays bombing at the finish line of the Boston Marathon. (Michael Dwyer / AP)

  • Boston Marathon Explosion

    First responders rush to help injured people after two explosions occurred along the final stretch of the Boston Marathon on Boylston Street in Boston, Massachusetts, U.S., on Monday, April 15, 2013. Two powerful explosions rocked the finish line area of the Boston Marathon near Copley Square and police said many people were injured. (Kelvin Ma / Bloomberg / Getty Images)

  • Boston Marathon Explosion

    Emergency workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. (AP Photo/Charles Krupa)

  • Boston Marathon Explosion

    There was smoke and panic in the street as emergency personnel responded to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (David L. Ryan / The Boston Globe / Getty Images)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: (EDITOR'S NOTE: THIS IMAGE CONTAINS GRAPHIC CONTENT) A person who was injured in an explosion near the finish line of the 117th Boston Marathon is taken away from the scene on a stretcher. (Photo by David L. Ryan/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

    A Boston police officer wheels in injured boy down Boylston Street as medical workers carry an injured runner following an explosion during the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria at the marathon's finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: Emergency personnel respond to the scene after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: A man lays on the ground after two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

    BOSTON - APRIL 15: Two explosions went off near the finish line of the 117th Boston Marathon on April 15, 2013. (Photo by David L. Ryan/The Boston Globe via Getty Images)

  • Boston Marathon Explosion

    Medical workers wheel the injured across the finish line during the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa)

  • An unidentified Boston Marathon runner, center, is reunited with loved ones near Copley Square following an explosion in Boston Monday, April 15, 2013. (AP Photo/Winslow Townson)

  • Boston Marathon Explosion

    Medical responders run an injured man past the finish line the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria of the Boston Marathon finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa)

  • Boston Marathon Explosion

    Medical workers aid injured people at the finish line of the 2013 Boston Marathon following an explosion in Boston, Monday, April 15, 2013. (AP Photo/Charles Krupa)

  • Boston Marathon Explosion

    A Boston police officer clears Boylston Street following an explosion at the finish line of the 2013 Boston Marathon in Boston, Monday, April 15, 2013. Two explosions shattered the euphoria at the finish line on Monday, sending authorities out on the course to carry off the injured while the stragglers were rerouted away from the smoking site of the blasts. (AP Photo/Charles Krupa)