The Officer Down Memorial Page for MIT Patrol Officer Sean Collier is here.
The case that gave birth to the "public safety exception" to Miranda is New York v. Quarles, 467 U.S. 649 (1984). The FBI's description of the public safety exception is here. Some analysis with particular relevance to this case is here. EDIT: The transcript of the suspect's initial appearance is here.
Outside links of interest are Orin Kerr's posts on House-to-House Searches and the Fourth Amendment and Tsarnaev and Miranda Rights.
Facial recognition software didn't help identify the Boston suspects, even though images of both were in databases.
Reddit's involvement in trying to crowdsource the case are discussed here (from the perspective of the sister of a misidentified suspect) and here (discussing Reddit's impact on the FBI's official investigation).
Here's a video that seems to blur the line at when a consentual search takes place.
Finally, my post on the shortcomings of citizen journalism.