Section 493. Attorneys forbidden to defend criminal prosecutions carried on by their partners, or formerly by themselves

An attorney, who  directly
  or indirectly advises in relation to, or aids or promotes the defense of
  any  action  or  proceeding  in  any  court, the prosecution of which is
  carried on, aided or promoted by a person as district attorney or  other
  public  prosecutor,  with  whom  such attorney is directly or indirectly
  connected as a partner; or who, having  himself  prosecuted  or  in  any
  manner  aided  or  promoted  any  action  of proceeding in any court, as
  district attorney or other public  prosecutor,  afterwards  directly  or
  indirectly  advises  in  relation  to, or takes any part in, the defense
  thereof, as attorney or otherwise; or who takes or receives any valuable
  consideration from or on behalf of any defendant  in  any  such  action,
  upon any understanding or agreement whatever, express or implied, having
  relation to the defense thereof, is guilty of a misdemeanor.