The state's anti-SLAPP statute was introduced as Senate Bill 807 by Sen. John Loudon on Dec. 3, 2003, passed the legislature May 13, 2004, and was signed by the governor. It becomes effective Aug. 28, 2004. The statute is substantially identical to a bill introduced during the previous legislative session, SB 268, which was not acted on. As in many states, the SB 807 was a response to a lawsuit (see Mandel et al. v. O'Connor et al. below). (Note! The bill proposed amending RSMo sec. 537.800, but the statute was codified at sec. 537.528.)
Denial of a special motion to dismiss under the state's anti-SLAPP statute is not a final judgment in the case and is not subject to interlocutory appeal.
Mandel et al. v. O'Connor et al.
Missouri Court of Appeals Eastern District, 2003
The mayor of Creve Coeur sued citizens for defamation after they criticized the mayor for not investigating possible city charter violations. The court affirms the trial court's summary judgment in favor of defendants.
State ex rel. Diehl v. Kintz
Missouri Court of Appeals Eastern District, 2005
Diehl was sued for defamation after he publicly spoke at a hearing on a company's application for a trash transfer station and distributed a handbill to the public opposing the application. Diehl's motion for dismissal was denied by the trial court. Diehl filed a petition for writ of mandate to force dismissal. The appellate court ordered the trial court to dismiss the suit for failure to state a claim upon which relief may be granted on the grounds that plaintiff could not succeed on its defamation complaint. The court notes that, although the state's anti-SLAPP statute (§ 537.528) "was not in effect to grant Diehl an immediate remedy, the same concerns that animated the legislature in enacting this statute may guide the exercise of our discretion in issuing a writ."