Don't bet on it, as a friend (L.A. County Sheriff) said to me, "the FBI couldn't follow a menstrating elephant in a snow bank"!
On most major cases that is true. If one checks over the years, almost all breaks in such cases were GIVEN to them by a citizen. At gumshoe work they have no interest and are not very good. If their case is to crack John Q. Public on some unimportant rap, they can solve that one. Case in point the anthrax case, even with several hundred men involved they are empty handed.