Mo. Rev. Stat. § 575.160: Interference with legal process — penalty.

1. A person commits the offense of interference with legal process if, knowing another person is authorized by law to serve process, he or she interferes with or obstructs such person for the purpose of preventing such person from effecting the service of any process.

2. "Process" includes any writ, summons, subpoena, warrant other than an arrest warrant, or other process or order of a court.

3. The offense of interference with legal process is a class B misdemeanor.