Section 215.11. Tampering with a witness in the third degree

A  person  is  guilty  of tampering with a witness in the third degree
  when, knowing that a person is about to be called  as  a  witness  in  a
  criminal proceeding:
    1.  He  wrongfully compels or attempts to compel such person to absent
  himself from, or otherwise to  avoid  or  seek  to  avoid  appearing  or
  testifying  at such proceeding by means of instilling in him a fear that
  the actor will cause physical injury to such person or  another  person;
  or
    2.  He  wrongfully  compels or attempts to compel such person to swear
  falsely by means of instilling in him a fear that the actor  will  cause
  physical injury to such person or another person.
    Tampering with a witness in the third degree is a class E felony.