The people of Watertown were awakened early Friday morning by the shootout that claimed the first suspect in the Marathon bombing case and then spent an eternal day in fear behind locked doors, feeling the terror that terrorists want you to feel.

The shutdown was finally ended early Friday evening, but the second suspect was still at large and the people had only just begun to venture from their homes when more shots were fired. Word spread that the police had the second suspect surrounded. The people waited and waited and then a voice crackled the good news over the police radio. The people of Watertown were already cheering when the news was tweeted by Boston police.

“CAPTURED!!! The hunt is over. The search is done. The terror is over. And justice has won. Suspect in custody.”

The moment then came to remember the officer who had been murdered the night before and the other officer who been seriously wounded. Those brave souls and the three innocents who had been killed in the bombing and the 170 who had been injured.

And nobody should forget that the suspects might very well still be at large with the makings of more bombs were it not for Jeff Bauman, who was just coming out of surgery where what remained of his legs had been removed at the knee when he groggily asked for a pen and paper.

“Bag. Saw the guy, looked right at me,” he wrote.

The note brought the FBI to Bauman’s bedside in intensive care. He said that a man in sunglasses and a black baseball hat had come up to him as he was waiting to see his girlfriend finish the Boston Marathon. The man had gazed straight at him and placed a black backpack at his feet and walked off. The bag had exploded minutes later.

With the description, the FBI searched surveillance video and the digital images sent in by the public until they found a “person of interest” in a black hat and black jacket, a black backpack on both shoulders. They would subsequently identify him as 26-year-old Tamerlan Tsarnaev, an ethnic Chechen who had come here from Kazakhstan in 2003 after his family was granted political asylum. His avowed goal had once been to get his American citizenship by boxing for the U.S. Olympic team and then turn pro.

That dream had hit a bump at the 2009 Golden Gloves Championship in Salt Lake City, where Tamerlan failed to make even the semifinals, losing by decision to Lamar Fenner of Chicago. He had hoped for a title bout but was arrested that year for assaulting his girlfriend. He stayed away from the gym for a while and came back transformed, abrasive and rude when he had once been polite and respectful. He walked with his street shoes on the mats as if to show rules did not apply to him.

In the meanwhile, his thwarted ambitions found refuge in talk of jihad. A YouTube account in the name “Tamerlan Tsarnaev” posted a playlist he named “Terrorists” and “liked” Islamic militant videos. He complained that “there are no values any more.”

After now spotting the “person of interest” described by Bauman in the images recovered from the area of the bombings, the FBI kept searching for other instances where he appeared. The next step was to see if he had been acting in concert with anybody.

The investigators soon came upon video footage of him walking in tandem with another young man wearing a baseball cap and carrying a backpack. They would later identify the second man as Tamerlan’s 19-year-old brother, Dzhokhar Tsarnaev.

Dzhokhar had been only 9 when the family arrived in America, and he seemed to have fully assimilated. He was a good-enough student to win a $2,500 college scholarship when he graduated high school from Cambridge Rindge & Latin School in 2011, a popular all-state wrestler and two-year captain of the team, popular and “chillaxed.” He worked for a time as a lifeguard at the Harvard pool.

“He was just a good kid,” says George MacMaster, the 56-year-old Harvard aquatics coordinator who had hired Dzhokhar as a lifeguard. “Did his job.”

MacMaster had not seen Dzhokhar since being deployed to Afghanistan in 2011 as a staff sergeant with the Massachusetts National Guard, having already served in Iraq and at a Guantánamo Bay. Dzhokhar had gone on to study marine biology at the University of Massachusetts, Dartmouth. His father, who had recently returned to the Russian republic of Dagestan, would describe him as a good student and “a true angel.”

But the kid who seemed to mix so well with the other kids in high school and who appeared to have such a bright future had fallen under the influence of the thwarted brother who had once allowed that he did not have “a single American friend.” Dzhokhar had not been averse to a little partying. But Tamerlan declared that a true Muslim has to swear off drink. Tamerlan also reportedly shunned such frivolities as pop music for songs such as “I Dedicate My Life to Jihad.”

When the FBI released the images of the suspects, there was Dzhokhar, walking a few paces behind Tamerlan. Dzhokhar’s cap was on backward and his backpack was slung over his right shoulder in the way of a student, but he followed his brother’s lead, matching his brother step for step, until Tamerlan paused to set down his backpack.

Dzhokhar continued on his own and placed his own backpack where the second bomb would soon explode. He paused to make a cellphone call and though the face is blurry, he appears to have a smirk. Any legitimate reason for feeling sorry for him because he fell under his brother’s spell ended as he left the backpack among the unsuspecting innocents.

After the bombings, Dzhokhar was seen around the gym and on campus at UMass, Dartmouth. Tamerlan spoke to their father that day in Dagestan. The father would later suggest to reporters that he was disappointed in his older son for having dropped out of school and gotten married, and he was anxious that it not happen with the younger son. Tamerlan was no doubt aware of this as he reassured his father on the very day of the bombing that Dzhokhar was studying and doing fine. The brothers might even have thought that they had gotten away with it. But Tamerlan had not imagined in that moment when he gazed straight at Bauman that this was another kind of championship, against someone who had more moxie than anybody he had ever encountered in the ring.

Tamerlan must have felt all-powerful and certain it was no contest as he set the bomb at Bauman’s feet. Tamerlan did not count on a quick-thinking civilian in a cowboy hat saving Bauman by tearing up a sweater to make tourniquets before the smoke of the blast had even cleared. And Tamerlan surely did not anticipate that Bauman would take the very first opportunity to ask for a pen and help the authorities catch him.

When the resulting images were released to the public, the brothers were identified only as Suspect 1 and Suspect 2, but they must have known it would not take long for somebody to name them. A friend called Dzhokhar and told him to be careful because he looked a lot like one of the suspects.

The brothers also must have known they could not remain in the vicinity of their home in Cambridge. Police now say the brothers were not the ones who robbed a convenience store in Kendall Square near MIT on Thursday night, though they did purchase gas at a gas station in Cambridge. Police cannot explain why the brothers allegedly went up to MIT Police Officer Sean Collier and shot him multiple times as he sat in his car, killing him.

Tamerlan and Dzhokhar are said to have next carjacked a Mercedes SUV, taking the driver with them, but he was either released or managed to escape at a gas station on Memorial Drive. The brothers then sped away, by some accounts tossing homemade explosives at police cars that were now pursuing them.

“They have explosives, some type of grenade,” a cop said on the radio at one point.

In Watertown, the SUV stopped and Tamerlan hopped out, firing at police. MBTA Transit Police Officer Richard Donahue was wounded in the shootout.

At one point, Tamerlan is said to have detonated an explosive device in the direction of the police. The blast might have blown back at him or perhaps a device they were throwing out of the car during the chase went off in the SUV. Or he might have been wearing some kind of suicide vest. He had wounds from shrapnel as well as bullets when he was taken to Beth Israel Deaconess Medical Center at 1:10 a.m.

The doctor on call lives nearby and had come running on hearing the gunfire. He joined the trauma team in trying to save the man who had allegedly inflicted horrific blast and shrapnel wounds on so many, killing three, including an 8-year-old boy. Tamerlan himself was pronounced dead at 1:35 a.m. A trigger for an explosive device was reportedly found on his body at the morgue.

Meanwhile, Dzhokhar had managed to drive away in the chaos, reportedly driving over his brother in his panic. The authorities shut down Boston, asking businesses to close and people to stay inside. A big section of Watertown was cordoned off and police began a methodical, door-to-door, nerve-straining search.

Among the Watertown residents who stayed in their homes was MacMaster, who had hired Dzhokhar as a lifeguard before deploying again to fight terrorism. MacMaster had returned in March and now watched from his window as police swarmed through the neighborhood in search of a seemingly nice, friendly, and well-assimilated young man turned suspected terror bomber.

“I’ve got a SWAT team in my backyard,” MacMaster reported over the phone.

He added that he is from Dorchester, near the home of Martin Richard, the 8-year-old who was killed in the bombings when the former lifeguard and his brother allegedly became indiscriminate dealers of death.

“Truth is stranger than fiction, that’s for sure,” MacMaster said.

Early Friday evening, shortly after authorities lifted the shutdown, a resident who lives not far from the previous night’s shootout emerged from his house and noticed that the white tarp covering the boat he keeps on a trailer in his backyard had been disturbed. He peered inside, saw a man covered with blood, and called the police.

Officer responded and a new flurry of gunshots erupted as they peered under the boat cover. The police backed off and tactical units that had just been departing the area returned. The FBI hostage rescue team arrived.

“Head toward the stern, middle of the boat,” a cop reported about the suspect.

Shortly before 9 p.m., there was a final loud noise, that of a stun grenade tossed into the boat by the same team that had rescued a 5-year-old boy held hostage in a bunker in Alabama in February. The grenade forced Dzhokhor to climb out of the boat and in the next moment he was handcuffed face down on the back lawn. Cops who had lost one of their own the night before rolled him over and immediately began treating wounds to his neck and leg that might have been fatal had he not been found. Word that the second suspect was in custody reached the crowd that had gathered at the perimeter. Cheers and applause rose into the darkness that suddenly held no more fear. Tactical officers came back up the street giving a thumbs-up.

Police had earlier recovered from a residence what was described as a significant amount of homemade explosives, by one report including a pressure-cooker bomb such as was used at the marathon. Bauman might very well have helped to prevent another attack with the quick and accurate description he gave the FBI.

"I am sure they were going to do something with those devices," said Boston Police Commissioner Ed Davis.

Bauman was recovering from his terrible wounds at a Boston hospital. His reflexive impulse in the moments after the blast had been to stand even though he had lost both his legs. He still had a champion’s spirit, and we are all in his debt.