The events in Boston overnight Thursday into Friday morning have been fast-moving and confusing at times.
By Friday evening, the second suspect, 19-year-old Dzhokhar Tsarnaev, was taken into custody after a tense stand-off. Here's the days events that led up the standoff:
- The FBI released photos and videos Thursday afternoon of two men they believed to be responsible for the bombing at Monday's Boston Marathon, which left three dead and injured more than 170.
- Shortly after 10 p.m., police received reports of a robbery at a 7-Eleven near the campus of MIT. Massachusetts State Police said Friday afternoon that the bombing suspects were not believed to have committed the robbery.
- Soon came reports of gunshots on the MIT campus, where campus police office Sean Collier, 26, of Somerville, Mass., was found dead in his cruiser with multiple gunshot wounds.
- About an hour later, two men hijacked a Mercedes SUV in Cambridge, holding the driver hostage for half an hour, while they visited three ATMs, making one successful withdrawal of $800, before releasing him. The victim says his assailants told him they had killed a campus police officer and claimed responsibility for the marathon bombings.
- Police spotted the stolen SUV and began a car chase during which the suspects began throwing explosives out a car window and exchanging gunfire. During the shootout, one of the men now identified as bombing suspect Tamerlan Tsarnaev, 26, was killed, and a Boston transit officer, 33-year-old Richard Donohue, was seriously injured. A second suspect, 19-year-old Dzhokhar Tsarnaev, apparently got away.
- Tamerlan was born in Russia and had been an accounting student at Bunker Hill Community College. A talented amateur boxer, he once harbored dreams of fighting on the U.S. Olympic team, a quest chronicled in a photo essay called "Will Box for Passport."
- His brother Dzhokar was born in Kyrgyzstan before moving to America as a youth. He graduated from Cambridge Rindge & Latin, one of the area's better public high schools, and two years ago was awarded a $2,500 scholarship for college. He became a naturalized citizen on Sept. 11, 2012. Friends recall him as "nice," "funny" and "light," while his father described him as a "true angel."
- Anzor Tsarnaev, the suspects' father, said via telephone from his home in Makhachkala, Russia, that he spoke with his sons earlier in the week, when they told him, "Everything is good, Daddy." He has asked his son to "surrender peacefully," but he also said that his boys "were set up" and warned that if authorities "killed (Dzhokar), then all hell would break loose."
- Meanwhile, in Cambridge, Mass., two people were taken into custody at the house where the suspects grew up. The people were not described as suspects or as being under arrest.
- Some 1 million residents throughout the metropolitan region were asked to stay inside Friday, as police have swarmed Watertown, Mass., with military-style vehicles and established a no-fly zone overhead. The stay-indoors request was lifted just after 6 p.m. ET.
- The Boston subway system, aka the "T," was shut down for much of the day, before being reopened just after 6 p.m. ET. The Boston Bruins and the Boston Red Sox postponed tonight's games.
- Just before 7 p.m. Friday, shots were fired in Watertown, near the site of the early morning shootout. Authorities believed a body or person was in a trailered boat in a backyard in Watertown, underneath a tarp, although it was unknown if this was the suspect. Police and military personnel quickly responded to the scene after the shots were fired, but authorities said they would proceed slowly and carefully.
- Just after 8 p.m. Friday, police began to close in on the boat in Watertown. Police believed the suspect, Dzhokar Tsarnaev, was hiding in the boat.
- At about 8:45 p.m., police said they took Tsarnaev into custody, alive. A crowd of bystanders erupted into cheers on the streets of Watertown.