据悉，波士顿警方当天凌晨出动9000多名警察，荷枪实弹，全城搜捕这名19岁疑犯。随后，警方在波士顿郊区一座住宅后院的一艘小艇上将其生擒。警方说，直升机通过热成像仪器发现藏身艇内的疑犯，抓捕过程中发生交火。
The moment police found the Boston 'bomber': Extraordinary thermal-imaging photos reveal wounded suspect hiding in a boat
Dramatic photographs reveal how breakthrough technology helped police home in on the second marathon bombing suspect 19-year-old Dzhokhar Tsarnaev.
The pictures reveal how state-of-the-art thermal imaging cameras helped police track the Chechen terror suspect while he hid on David Henneberry's boat for his final stand off in Watertown following a terrifying week of violence.
Henneberry called 911 after spotting blood and what he thought was a crumpled body in his boat, which was sitting in the backyard of his home.
Authorities then used a helicopter equipped with a thermal imaging device to confirm that there was a body in the tarp covered boat and that the person was alive.
In hiding: Dzhokhar was discovered by Massachusetts resident David Henneberry hiding in his boat. Police used thermal imaging to monitor his movements
Tracked: This is how officers monitored Dzhokhar in the boat as he lay there unaware he was moments from capture
Revealed: How heat sensors found the Boston terror suspect - the cameras showed how the man moved around the boat
Hovering over the area, the helicopter spotted the heat signature of a person, confirming Henneberry's suspicions.
'Our helicopter had actually detected the subject in the boat,' Col. Timothy Alben of the Massachusetts State Police told NBC News. 'We have what's called a FLIR — a forward-looking infrared device — on that helicopter.
The chopper monitored the body in the boat for more than an hour before police moved in and took the bleeding Dzhokhar Tsarnaev into custody.
He remained in hospital today and was described as clinging to life as Gov. Deval Patrick said: 'I hope he survives, because we have a million questions.'
The secret service's top interrogators are now waiting to quiz him as he is treated in the same hospital where 11 victims are still recovering.
Thermal imagers are able to detect a body or other heat source inside a house, a vehicle, or in this case, a boat, because heat, unlike visible-light wavelengths can pass through walls.
Police regularly use them to find out whether marijuana is being grown inside a house with heat lamps.
A nightmarish 24 hours came to an end in Boston at around 8:45pm yesterday as the 19-year-old suspect was taken into custody alive but injured after a gun battle with police and federal agents.
It signaled the end of five days of terror set-off by the double bombing at the marathon finish line.
The mayor of Boston, Thomas Menino, was quoted by the Boston Globe as taking to the police scanner to exclaim, 'We got him'.
'I have never loved this city and its people more than I do today. Nothing can defeat the heart of this city .. nothing.'
Relieved law enforcement officers began cheering and clapping after he was arrested and thousands of jubilant members of the public took to the streets to salute their hard work.
Dzhokhar's older brother, Tamerlan Tsarnaev, 26, lay dead following a furious fire-fight alongside his younger brother with police on Thursday which left one officer dead. 
Hi-tech: Boston police deployed all the technology they have to track down Dzhokhar
Busted: The robotic arm pulls back the boat cover to reveal the hiding terror suspect
Assisted: This striking picture shows Dzhokhar Tsarnaev lying on the ground of the property of 67 Franklin Street in Watertown after authorities apprehended him. He had to have medical assistance to breathe
Security: Law enforcement officials stand guard outside the West Clinical Center, pictured, where Boston bombing suspect Dzhokhar Tsarnaev is being treated
Wounded: This still frame from video shows Boston Marathon bombing suspect Dzhokhar Tsarnaev visible through an ambulance after he was captured in Watertown on Friday
This image obtained April 19, 2013 courtesy CBS News shows Dzhokhar Tsarnaev, a suspect in the Boston Marathon bombing who was captured Friday night, April 19, 2013 after he was found hiding in a boat in a Boston suburb
Aerial views of 67 Franklin Street, Watertown, Massachusetts. Boston bombing suspect #2 Dzhokhar A. Tsarnaev, 19, led the authorities to 67 Franklin Street in Watertown, Massachusetts where he was taken into custody
A light beam from a helicopter, top right, aims in the direction of Watertown, where officials searched for a suspect in the Boston Marathon explosions all Friday
Henneberry became the day's unusual hero when he decided to check on his beloved boat moments after police lifted a Boston-wide lock-down believing they wouldn't find the younger suspect.
On spotting him inside Henneberry 'freaked out' and ran inside to call police - who dispatched the helicopter
'He looked and noticed something was off about his boat, so he got his ladder, and he put his ladder up on the side of the boat and climbed up, and then he saw blood on it, and he thought he saw what was a body laying in the boat,' Henneberry's neighbor, George Pizzuto told ABC News.
'So he got out of the boat fast and called police.'
'That boat's his baby. He takes care of it like you wouldn't believe. And they told him it's all shot up,' Pizzuto said. He's going to be heartbroken.'
Within minutes police, ATF, SWAT and K-9 units had descended upon 67 Franklin Street and engaged Tsarnaev in a vicious gun battle - over 40 shots rang out in the quiet suburban neighborhood.
'There was an exchange of gunfire,' confirmed Boston Police Commissioner Ed Davis at a news conference.
Authorities, using a bullhorn, had called on the suspect to surrender: 'Come out with your hands up.'
'We used a robot to pull the tarp off the boat,' David Procopio of the Massachusetts State Police said to CNN. 'We were also watching him with a thermal imaging camera in our helicopter. He was weakened by blood loss -- injured last night most likely.'
Applause: A police officer breaks into a smile as the crowd applaud him on the news of the arrest of one of the Boston Marathon bombing suspects, Friday, April 19, 2013, in Boston
Celebration: Crowd gathered to celebrate in the Boston Common after both marathon bombing suspects were found
Unconfirmed reports suggest that Tsarnaev was shot twice by law enforcement in the gun battle which raged until his capture at approximately 8.45pm.
Law enforcement sources have suggested that Tsarnaev gave himself up voluntarily after realizing continuing resistance was fruitless.
President Barack Obama praised the outcome after a 'tough week' but said the focus would now be on getting answers for the victims.
He said: 'Why did young men who grew up and studied here as part of our communities and our country resort to such violence?'
'We've closed an important chapter in this tragedy,' added Mr. Obama said in his televised address.
Federal law enforcement officials are invoking the public safety exception to the Miranda rights.
That means that Tsarnaev will be questioned immediately without having his rights read to him.
Republican Senators John McCain and Lindsey Graham have called for Tsarnaev to be held as an enemy combatant, although the chances of that being permitted are slim.
Massachusetts Governor Deval Patrick speaks during a news conference announcing the capture of Dzhokhar Tsarnaev, the second suspect in the Boston Marathon bombing
State Police Col. Timothy Alben, accompanied by Massachusetts Governor Deval Patrick, speaks during a news conference as U.S. Attorney Carmen Ortiz, (right) addresses the crowd
Cheering for Heroes: Two women applaud after the arrest of a suspect of the Boston Marathon bombings in Watertown on Friday evening
'We Got Him': Watertown residents along Arsenal Street cheer for police officers after the capture of Dzhokhar Tsarnaev four days after the dual bombings at the Boston Marathon in Watertown, Massachusetts
President Obama said it was important justice was 'done right'.
'In this day of instant reporting, tweets, and blogs, there is a temptation to latch onto any bit of information, sometimes to jump to conclusions, but when a tragedy like this happens, with the public safety at risk and the stakes so high, it important to do this right,' Obama said.
'That's why have an investigation, that's why we relentlessly gather the facts, that's why we have courts.'
'Whatever hateful agenda drove these men cannot, will not prevail,' he said, 'and whatever they thought they could achieve failed because the people of Boston refuse to be intimidated, and we as Americans refuse to be terrorized.'
The two suspects were ethnic Chechens from southern Russia who had been in the U.S. for about a decade and lived in Cambridge, Massachusetts. Investigators still have given no details on the motive for the bombing.
Early on Friday morning, 26-year-old Tamerlan Tsarnaev was killed in a ferocious gun battle and car chase during which he and his younger brother hurled explosives at police from a stolen car, authorities said. The younger brother managed to escape.
During the getaway attempt, the brothers killed Sean Collier, an MIT policeman, and severely wounded another officer, authorities said.
Chechnya has been the scene of two wars between Russian forces and separatists since 1994, in which tens of thousands were killed in heavy Russian bombing. That spawned an Islamic insurgency that has carried out deadly bombings in Russia and the region, although not in the West.
The older brother had strong political views about the United States, said Albrecht Ammon, 18, a downstairs-apartment neighbor in Cambridge. Ammon quoted Tsarnaev as saying that the U.S. uses the Bible as 'an excuse for invading other countries.'
It has emerged the FBI interviewed the older brother at the request of Russia in 2011 but dropped their surveillance after finding nothing they thought was worth following up.
After a tense all-day manhunt for Dzhokhar and house-to-house search by thousands of SWAT team officers with rifles and armored vehicles, Dzhokhar was cornered in a homeowner's yard.
Members of the public cheer as police officers leave the scene where Dzhokhar Tsarnaev, the surviving suspect in the Boston Marathon bombings, was taken into custody in Watertown, Massachusetts on Friday
Thank You: Members of the public cheer as police officers leave the scene where Dzhokhar Tsarnaev, the surviving suspect in the Boston Marathon bombings, was taken into custody
Two unidentified young men drive with an American Flag through Watertown, Massachusetts, USA, 19 April 2013, after Law Enforcement Officials apprehended Boston Marathon Bombing suspect, Dzhokhar Tsarnaev
Hundreds of Northeastern University students gather in Hemenway Street to celebrate the capture of suspected Boston Marathon bomber Dzhokhar Tsarnaev in Boston on April 19th
High Five Flying Flag: A policeman (left) celebrates with a woman after one of the Boston bombers was apprehended on Friday while Frank McGillin, who has ran three Boston Marathons, waves a U.S. flag
Police officers high-fived each other and shook hands at the conclusion of the fire-fight ended with him arrested.
One police officer, a look of relief on his face, said: 'Yep, we got him.'
Chants of 'USA! USA!' broke out. In Boston, people danced in the streets outside Fenway Park.
Another officer was hugged by a woman standing at a barricade set up at a road several blocks from Franklin Street. As word quickly spread crowds cheered and clapped.
Dozens of police walked back from Franklin Street with their weapons lowered or holstered. Several chatted on cell phones as they presumably called loved ones to tell them the hunt was over and they were safe.
'Thank you. Thank you. It was our pleasure,' members of the Boston SWAT team said over a loudspeaker to the relieved crowds who gathered to thank them.
An estimated 1,000 law enforcement officers had been involved in the massive police manhunt.
Just prior to this, police fueled the paranoid atmosphere when they said three other people were taken into custody for questioning at an off-campus housing complex at the University of the Massachusetts at Dartmouth where the younger man may have lived.
Authorities are still holding the three people in custody in New Bedford, Massachusetts, 65 miles south of the city, the Boston Globe reports.
It is unknown how they were connected to the case.
At least seven IEDs were found, some in Watertown and some at a home in Cambridge, which police made safe.
Fist Pump: A SWAT officer raises his fist in Watertown, Mass. Friday, April 19, 2013, after the manhunt for the second of two suspects in the Boston Marathon bombing was captured
'We Got Him!': Twenty four hours of chaos comes to an end: How Dzhokhar Tsarnaev was apprehended by police after day-long search
April 18 5.30pm - The FBI releases CCTV footage and stills of two suspects from surveillance cameras near the explosion sites filmed shortly before the blasts. FBI agent Richard DesLauriers asks for the public's help in identifying the men who are both wearing baseball caps and carrying backpacks. 'We consider them to be armed and extremely dangerous,' Mr DesLauriers said, warning that they should not be approached.
10.30pm - A campus police officer is shot and killed at Massachusetts Institute of Technology (MIT) in Cambridge, near Boston, after responding to a report of a disturbance.
Shortly afterwards, police get a report of a carjacking nearby. The two men are suspected of killing the MIT police officer, then stealing the car at gunpoint and later releasing its driver unharmed. The suspects threw explosives from the car as police followed it to the Boston suburb of Watertown.
April 19 1am - Witnesses report hearing multiple gunshots and explosions in Watertown. Residents are advised to keep their doors locked and not let anyone in. TV footage shows armed officers surrounding a suspect lying on the ground.
Police later say one of the two suspects in the MIT officer shooting is dead but the other, who is tied to the Boston marathon bombing, remains at large.
Public transport is suspended in the Boston area as the hunt for the remaining suspect continues.
A new photo of him on the loose is released showing him in a grey hoodie sweatshirt at a 7-Eleven store in Cambridge.
5pm - Police admit at a press conference they don't know where 19-year-old Dzhokhar A. Tsarnaev is. Authorities lift 'shelter in place' orders and allow residents to venture outside.
5.45pm - David Henneberry finds a body in his boat on Franklin Street in Watertown, less than three quarters of a mile from where Tsarnaev ditched his stolen Mercedes SUV.
6pm - Officers surround Mr Hennerberry's boat and exchange fire with him.
7.05pm - Flash grenades are reportedly tossed into the boat to stun Tsarnaev.
8.43pm - Tsarnaev surrenders and it taken into custody. He is rushed to the hospital by ambulance
Endgame: An ambulance carries Boston Marathon bombing suspect Dzhokhar Tsarnaev from the scene after he was apprehended in Watertown, Massachusetts, USA on Friday (left) as Police SWAT teams leave the area (right)
Drama: Boston bombing suspect Dzhokhar Tsarnaev is believed to have been taken in this ambulance and taken to Mt. Auburn hospital in the city to be treated for his wounds
This map shows the location of incidents surrounding the manhunt for the two Boston Marathon bombings suspects and includes an updated timeline of events and information on the Tsarnaev brothers
Terrorists: Tamerlan Tsarnaev (right) was killed during an exchange of gunfire with police on Wednesday night. His younger brother Dzhokhar (left) is still on the run and reportedly has explosives strapped to his body
It emerged earlier in the day that Dzhokhar had several active online profiles and even posted messages warning people to 'stay safe' after the bombings - an apparent attempt to cover his tracks.
The 19-year-old, who attended Cambridge Rindge and Latin School and was a registered student at University of Massachusetts - Dartmouth, was also a 9/11 denier and posted a chilling message on Twitter eight months ago where he wrote: ‘Boston marathon isn’t a good place to smoke'.
The tweet last August appeared on the micro-blogging site from user @J_Tsar - named in multiple reports as an alias for the man behind Monday’s atrocity. He also tweeted about his intent to grow a beard and how he ‘wanted out’ of American life.
The messages suggested the level of forethought and planning that the Chechen immigrants allegedly put into the devastating attack on Boston.
The tweets added to a picture of Dzhokhar which was emerging on Friday, as a young man who had hidden his sinister intentions beneath the facade of a party-loving but dedicated student who was captain of his high school wrestling team.
Dzhokhar Tsarnaev, emerged as the FBI's 'Suspect 2' on Thursday after he was seen on CCTV wearing a white baseball cap and dropping a backpack shortly before the huge blasts.
The older brother Tamerlan attended Bunker Hill Community College and was studying to become an engineer but took a year off to pursue boxing.
On the move: Several different agencies including the Boston police, FBI and SWAT teams were working together
Constant danger: Scores of police and SWAT team members were surrounding the Boston suburb on Friday morning
He said in an interview with a Boston University student magazine in 2010: 'I don't have a single American friend. I don't understand them.'
The 26-year-old had a profile on YouTube channel since August 2012. Five months ago, Tamerlan created a playlist dedicated to terrorism.
Named simply ‘Terrorists,’ the playlist included a pair of videos, which are now no longer available. Although most of the clips in the channel are ordinary music videos, Tamerlan Tsarnaev’s YouTube channel shows signs that he had been drawn to radical Islamism.
Among the songs on his playlists was one called ‘I will dedicate my life to Jihad.' He also featured videos recorded by recent converts to Islam.
Many members of the family denounced the two men and the suspects' uncle Ruslan Tsarni of Montgomery Village, Maryland, pleaded on television for Dzhokhar to give up.
'Dzhokhar, if you are alive, turn yourself in and ask for forgiveness,' he said.
The 19-year-old's father on Saturday pleaded for him to tell police 'everything'. 'Just be honest,' he said.
Video of SWAT raid on Watertown house
Student: Dzhokhar Tsarnaev (left) graduated from his Cambridge high school and was in college studying medicine. He is on the run after his brother Tamerlan (right) was killed after they were named terror suspects
High alert: State police arrest an unidentified man walking at the University of Massachusetts - Dartmouth campus during their sweep of the university on Friday
Stay indoors: A resident views police in tactical gear conduct a search for a suspect in the Boston Marathon bombings
"Shelter in place": Boston residents asked to stay indoors
Heroes: MIT campus police officer Sean Collier, 26, (left) was shot dead by the fleeing terror suspects. Officer Richard Donohue, 33, (right) was injured in the exchange of gunfire but is now in a stable condition in hospital
Boston bombing suspects, Tsarnaev brothers, caught on video
This combination of Associated Press file images released by the FBI on Thursday show two images taken from surveillance video of what the FBI are calling suspect number 1, (left), in black cap,and suspect number 2, (right), in a white cap
Map showing the Boston crime scene perimeter where experts are trying to piece together the clues left behind the deadly marathon explosion
