Couple of examples:

Antonio Caponigro (Consigliere) - Killed Angelo Bruno

Sonny Red Indelicato (Capo) - Involved in a hit

Its pretty rare for the administration to carry out hits, but you hear of a captain doing some dirty work every now and again. It used to bewilder me why a captain who probably has about 40 guys working for him who could do the muscle work but now I think I understand that most of its about clandestine knowledge. For example, Anthony Caponigro would rather kill Angelo Bruno himself rather than get a soldier or an associate to do it for him, as one of those underlings might run and tell Bruno about the plan in order to get in his good graces, so it is not worth Caponigro taking that risk of himself getting whacked.

Although sometimes it does make me wonder my a soldier who is given the order to kill some low-level hood dosen't just get one of his associates to do it for him in order to avoid FBI scrutiny. You usually here more about soldiers doing hits rather than associates and I always found that a bit strange.