How long until we know?  —  It's been more than 24 hours since the explosions in Boston.  But while new details emerge by the hour, the question on so many people's minds remains unanswered: Who did it?  —  “The range of suspects and motives remains wide open,” FBI Special Agent Richard DesLauriers said …

Injured Saudi is a witness, not a suspect, in Boston bombing  —  U.S. law enforcement officials said Tuesday that a Saudi national injured in the Boston Marathon bombing is regarded as a witness, not a suspect.  —  The Saudi, who is recuperating at a Boston hospital, is in his 20s …

Reinhart-Rogoff, Continued  —  I was going to post something sort of kind of defending Reinhart-Rogoff in the wake of the new revelations — not their results, which I never believed, nor their failure to carefully test their results for robustness, but rather their motives.

Bomb Details Emerge in Boston Case  —  BOSTON — The explosives used to kill three people and injure 176 at the Boston Marathon on Monday were likely some kind of “pressure-cooker” devices that sent sharp bits of shrapnel flying into victims in the vicinity of the blast, several law enforcement officials said Tuesday.

Why Boston Bombings Might Be Scarier Than 9/11  —  Killing Americans at play resonates differently than attacks on economic and military targets.  —  Call it “terrorism” if a label helps you make sense of this madness.  Find who did it and squash him—or them—with what President Obama called “the full weight of justice.”

Envelope tests positive for ricin at Washington mail facility  —  Washington (CNN) — An envelope that tested positive for the deadly poison ricin was intercepted Tuesday afternoon at the U.S. Capitol's off-site mail facility in Washington, congressional and law enforcement sources tell CNN.