I picked up this technique from a Kalen Delaney article that I can't seem to find now. Might not help if it was not a recent transaction.

DECLARE @a NVARCHAR(MAX) = N''

DECLARE @b-2 VARBINARY(MAX)

SELECT @a = [Transaction ID] FROM fn_dblog(NULL, NULL) WHERE [Transaction Name] = N'DROP'

SELECT @b-2 = MAX([Transaction SID]) FROM fn_dblog(NULL, NULL) WHERE [Transaction ID] = @a

SELECT SUSER_SNAME(@b)