A mystifying development in the investigation of the alleged Boston Marathon bombing suspects occurred early Wednesday morning when An F.B.I. agent shot and killed a Chechen man named Ibragim Todashev in Orlando, Florida.
Todashev was reportedly friends with the elder Boston Marathon bombing suspect, Tamerlan Tsarnaev. The police and F.B.I. were questioning Todashev on his and Tamerlan Tsarnaev's involvement in the unsolved murders of three men in 2011 when, according to Takeaway partner The New York Times, he exploded and attacked an F.B.I. agent with a sharp object.