9:48 AM PT: In case you missed it earlier, Mass. Gov. Deval Patrick led a briefing with the state police a few moments ago. There wasn't much new, but they urged Boston area residents to continue staying at home and to only open the door for uniformed law enforcement. They also said they do not have a suspect in custody and that they've gone through about 60-70 percent of the homes in the area they are searching. Lastly, they said there will be a controlled explosion on Norkfolk St. in Cambridge later today. This doesn't necessarily mean they know that there is a bomb at the location, but that they at least have concerns about the possibility of a booby trap.
9:51 AM PT: According to NBC, the elder Tsarnaev flew from JFK to Russia last year for six months, from January 12 to July 17, 2012. The Tsarnaev's father lives in Russia. Also according to NBC, the younger brother became a U.S. citizen on September 11, 2012.
10:00 AM PT: On the lighter side:
"At the direction of authorities, select Dunkin' Donuts restaurants in the Boston area are open to take care of the needs of law enforcement and first responders."