WATERTOWN, Mass. (AP) -- Lifting days of anxiety for a city and a nation on edge, police captured the surviving Boston Marathon bombing suspect, found bloodied in a backyard boat Friday night less than 24 hours after a wild car chase and gun battle that left his older brother dead and Boston and its suburbs sealed in an extraordinary dragnet.
"We got him," Boston Mayor Tom Menino tweeted. A cheer erupted from a crowd gathered near the scene.
"CAPTURED!!!" police added later. "The hunt is over. The search is done. The terror is over. And justice has won. Suspect in custody."
During a long night of violence Thursday and into Friday, brothers Dzhokhar and Tamerlan Tsarnaev killed an MIT police officer, severely wounded another lawman and hurled explosives at police in a desperate getaway attempt, authorities said.
Late Friday, less than an hour after authorities said the search for Dzhokhar had proved fruitless, they tracked down the 19-year-old college student holed up in the boat, weakened by a gunshot wound after fleeing on foot from the overnight shootout with police that left 200 spent rounds behind.
He was hospitalized in serious condition, unable to be questioned about his motives.
Tamerlan Tsarnaev, 26, died in the shootout early in the day. At one point, he was run over by his younger brother in a car as he lay wounded, according to investigators.
The violent endgame unfolded four days after the bombing and just a day after the FBI released surveillance-camera images of two young men suspected of planting the pressure-cooker explosives that ripped through the crowd at the marathon finish line, killing three people and wounding more than 180.
The two men were identified by authorities and relatives as ethnic Chechens from southern Russia who had been in the U.S. for about a decade and were believed to be living in Cambridge, just outside Boston. But investigators gave no details on the motive for the attack.
President Barack Obama said the nation owes a debt of gratitude to law enforcement officials and the people of Boston for their help in the search. But he said there are many unanswered questions about the Boston bombings, including whether the two men had help from others. He urged people not to rush judgment about their motivations.
The breakthrough came when a man in a Watertown neighborhood saw blood on a boat parked in a yard and pulled back the tarp to see a man covered in blood, authorities said. The resident called 911 and when police arrived, they tried to talk the suspect into getting out of the boat, said Boston Police Commissioner Ed Davis.
"He was not communicative," Davis said.
Instead, he said, there was an exchange of gunfire -- the final volley of one of the biggest manhunts in American history.
Watertown residents who had been told in the morning to stay inside behind locked doors poured out of their homes and lined the streets to cheer police vehicles as they rolled away from the scene.
Celebratory bells rang from a church tower. Teenagers waved American flags. Drivers honked. Every time an emergency vehicle went by, people cheered loudly.
"They finally caught the jerk," said nurse Cindy Boyle. "It was scary. It was tense."
Police 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.
"Tonight, our family applauds the entire law enforcement community for a job well done, and trust that our justice system will now do its job," said the family of 8-year-old Martin Richard, who died in the bombing.
The FBI was swamped with tips -- 300,000 per minute -- after the release of the surveillance-camera photos, but what role those played in the overnight clash was unclear. State Police spokesman Dave Procopio said police realized they were dealing with the bombing suspects based on what the two men told a carjacking victim during their night of crime.
The search by thousands of law enforcement officers all but paralyzed the Boston area for much of the day. Officials shut down all mass transit, including Amtrak trains to New York, advised businesses not to open, and warned close to 1 million people in the entire city and some of its suburbs to unlock their doors only for uniformed police.
Around midday, the suspects' uncle, Ruslan Tsarni of Montgomery Village, Md., pleaded on television: "Dzhokhar, if you are alive, turn yourself in and ask for forgiveness."