(1) A person commits bribery of a witness if he offers, confers, or agrees to confer any benefit upon a witness or a person he believes is about to be called as a witness in any official proceeding with intent to:
(a) Influence him to testify falsely or unlawfully withhold any testimony; or
(b) Induce him to avoid legal process summoning him to testify; or
(c) Induce him to absent himself from an official proceeding to which he has been legally summoned.
(2) Bribery of a witness is a Class IV felony.
(3) A person who is a witness or has been called as a witness in any official proceeding commits a Class IV felony if he accepts or agrees to accept any benefit from any other person for the purposes set forth in subsection (1) of this section.