10 things we know right now about the Boston bombing case

Boston celebrates, the President promises answers and the second guessing begins

<p>A police cruiser drives by as people react to news of the arrest of one of the Boston Marathon bombing suspects, Friday, April 19, 2013, in Boston. Boston Marathon bombing suspect Dzhokhar Tsarnaev was captured in Watertown, Mass. The 19-year-old college student wanted in the bombings was taken into custody Friday evening after a manhunt that left the city virtually paralyzed and his older brother and accomplice dead. (AP Photo/Julio Cortez)</p>

A police cruiser drives by as people react to news of the arrest of one of the Boston Marathon bombing suspects, Friday, April 19, 2013, in Boston. Boston Marathon bombing suspect Dzhokhar Tsarnaev was captured in Watertown, Mass. The 19-year-old college student wanted in the bombings was taken into custody Friday evening after a manhunt that left the city virtually paralyzed and his older brother and accomplice dead. (AP Photo/Julio Cortez)

(Julio Cortez, AP Photo)

1. Boston celebrated the arrest of 19-year-old Dzhokar Tsarnaev.

2. Boston Mayor Tom Menino celebrated.

3. The arrest marked the end of a long day … and, obviously, a long week in the city.

4. Watertown resident Andrew Kitzenberg, aka @AKitz, is back at home.

5. U.S. President Barack Obama promised a full investigation.

“Obviously, tonight there are still many unanswered questions — among them: Why did these young men who grew up in our country and studied here as part of our communities and our country resort to such violence?

“How did they plan and carry out these attacks and did they receive any help?”

He used his Saturday-morning address to thank first responders, doctors and “the big-hearted people of Boston.”

6. The family of eight-year-old victim Martin Richard released a statement after news of the arrest:

“Our community is once again safe from these two men. None of this will bring our beloved Martin back, or reverse the injuries these men inflicted on our family and nearly 200 hundred others. We continue to pray for healing and for comfort on he long road that lies ahead for every victim and their loved ones.”

7. The fourth victim, Sean Collier, was known for his irrepressible grin. The 26-year-old’s life-long dream was to be a police officer. MIT police chief John DiFava called Collier a man for whom police work was a calling. “He was born to be a police officer.”

8. CNN reported on Saturday morning that bombing suspect Dzhokar Tsarnaev was in serious condition in a Boston hospital. The news network also suggested he could be in a courtroom as early as Saturday, if physically able.

9. Jeff Bauman, who lost both his legs in Monday’s blasts, is credited with helping investigators solve the case. Bloomberg told the story here, then Slate revisited the story to consider its merits: “Given Jeff Bauman’s location at the time of the blast, and what we now know about the suspects, his brother’s version certainly appears possible and maybe even likely.”

10. From the attack to the aftermath, the second guessing has begun.