While on probation, Farina cannot own or carry a gun, Mateljan said.
A former policeman, Farina was arrested May 11 for having a .22 caliber semiautomatic handgun in his briefcase. He promptly apologized after his release, saying he forgot he had the gun in his baggage.
Farina, 64, did not appear in court Thursday.
Farina has appeared in numerous TV shows and movies, including a three-year stint on "Law & Order" as detective Joe Fontana.
Other charges of carrying a concealed weapon and carrying a loaded firearm were dismissed.