525.15 COMMUNICATIONS TO PRISONERS.
   (a)   No person shall convey to any prisoner in any prison or penal institution or in the custody of any police officer, sheriff or other peace officer, any letter or written or printed or code communication, except by permission of the person responsible for the custody of such prisoner. (1931 Code §91.1321)
   (b)   Whoever violates this section is guilty of a misdemeanor of the first degree.