See this
link:
(S)ection 179.85 of the regulations provides, in pertinent part, as follows:
A certificate of the local chief of police, sheriff of the county, head of the State police, State or local district attorney or prosecutor, or such other person whose certificate may in a particular case be acceptable to the Director, shall be completed on each copy of the Form 4 (Firearms). The certificate shall state that the certifying official is satisfied that the fingerprints and photograph accompanying the application are those of the applicant and that the certifying official has no information indicating that the receipt or possession of the firearm would place the transferee in violation of State or local law or that the transferee will use the firearm for other than lawful purposes.
As a general rule, the following can sign:
* Chief of Police for your town
* Sheriff for your county
* Chief of state police for your state
* District Attorney for your area
* Prosecutor for your area
* State Attorney General for your state
* Judges for your state, with some limitations
* Head of state Fish & Game Department as CLEO for wildlife issues
* Anyone who has been delegated the authority to sign for one of the above
Some state specific ones are:
* Alaska State Troopers
* Georgia Bureau of Investigation, Director of the GBI Crime Info Center, (404) 244-2605
* Vermont State Police