The events in Boston overnight Thursday into Friday morning have been fast-moving and confusing at times.
Here's where things stood on Friday afternoon:
- 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 have been asked to stay inside, as police have swarmed Watertown, Mass., with military-style vehicles and established a no-fly zone overhead.
- The Boston subway system, aka the "T," remains shut down, while taxi service has been partiality restored. The Boston Bruins and the Boston Red Sox postponed tonight's games.
Photo Credit: AP