Who are you speaking of?
If referring to start of ME2, I don't think we know who blows up the Normandy. It is Cerberus who hires someone to find Shepard's body later.
Nope. Check Mass Effect: Redemption. The Collectors (!) hire the Shadow Broker (!) to recover the body. However, Liara T'Soni (!) barges in and screws everyone up, recovers the stasis pod, and only then Miranda Lawson and the Cerberus cavalry arrive and convince her to provide Shepard to Project: Lazarus.
^ Hmm, not exactly.. Cerberus contacts Liara BEFORE she gets Shepard's body and provides her with a lead. I'd delete this question, since it's unintelligible, but since people already answered, I guess it has to turn into useful discussion :D