Mo. R. Civ. P. 94 · "State ex rel." actions
Missouri kept the traditional name and a recognizable version of the historical procedure. The petition is still styled "State ex rel."; the court still issues a preliminary order before deciding whether the writ should be made peremptory; and original jurisdiction lies concurrently in the circuit court, the court of appeals, and the Supreme Court of Missouri.
Where New York and New Jersey rebuilt the writ inside modern procedural rules, and Texas turned it into a working tool of appellate practice, Missouri did the most conservative thing of the four: it kept the writ's traditional name, its sovereign caption, and an updated version of its historical procedure. The result is the most readable version of mandamus practice for anyone familiar with the writ's English-law origins.
The constitutional foundation is Missouri Constitution article V, section 4, which vests the Supreme Court of Missouri, the courts of appeals, and the circuit courts with concurrent original jurisdiction to issue writs of mandamus and other remedial writs. The procedure is implemented by Mo. R. Civ. P. 94, which sets out the requirements for the petition, the court's response, and the form of relief. Petitions are styled in the traditional manner — "State ex rel. [relator] v. [respondent]" — signaling that the writ is issued not on the private initiative of the petitioner but at the suit of the State, exercising its prerogative to require its officers to do their duty.
The substantive standard is also recognizably classical. Mandamus in Missouri is available to compel the performance of a clear, present, and unqualified ministerial duty owed by a public officer to the relator. The writ does not lie to compel the exercise of discretion in a particular way; it lies only to compel action where the duty is non-discretionary, or to compel a discretionary officer to act at all where the officer has refused to exercise discretion in any direction.
Rule 94 lays out a procedural path that will feel familiar to anyone who has studied the historical writ. The relator petitions for the writ; the court decides, on the strength of the petition and any suggestions in support, whether to issue a preliminary order requiring the respondent to answer; the respondent answers; and the court then decides whether to make the writ peremptory or to discharge the preliminary order.
The relator files a petition setting out the facts establishing the respondent's duty, the relator's clear right to performance, and the relief sought, accompanied by suggestions in support and any documentary exhibits essential to understanding the matter. Rule 94 specifies that the petition shall be supported by exhibits where necessary, and good practice attaches the relevant orders, correspondence, or administrative materials at the outset.
On reviewing the petition, the court issues a preliminary order in mandamus directing the respondent to answer, issues a peremptory writ outright in a clear case, or denies the petition. The preliminary order is issued in the name of the State on the relation of the relator and is served along with the petition. In modern practice, the preliminary-order route is the customary middle path.
The respondent files an answer to the petition within the time fixed by the preliminary order, admitting or denying the allegations and raising any defenses. Failure to answer within the time specified can result in entry of judgment for the relief requested in the petition. Suggestions in opposition that the respondent filed before the preliminary order do not substitute for the formal answer.
After briefing — and, in cases that require it, oral argument — the court either makes the writ peremptory (commanding the respondent to perform the duty) or discharges the preliminary order. A peremptory writ in Missouri is the final adjudicative form of relief, equivalent to a judgment, and is appealable under ordinary appellate rules.
The Missouri Constitution gives the circuit court, the court of appeals, and the Supreme Court of Missouri concurrent original jurisdiction over mandamus. As a practical matter, the level of court chosen should match the level of the official whose action is being compelled and the systemic importance of the issue. Mandamus against a trial court will typically go to the court of appeals; mandamus against a statewide officer or on a matter of statewide importance may be filed directly in the Supreme Court; mandamus against a county or municipal officer will often start in the circuit court.
The classical mandamus standard turns on the ministerial-versus-discretionary distinction. Missouri practice tracks that distinction closely, and the most common ground of denial is a finding that the duty at issue is discretionary rather than ministerial.
| Ministerial Duty (Mandamus Will Lie) | Discretionary Function (Mandamus Will Not Lie) | |
|---|---|---|
| Nature of the obligation | A duty so plainly prescribed by law that the officer has no discretion to refuse | A function that requires the officer to weigh facts, exercise judgment, or choose among permitted alternatives |
| What the court orders | The officer must perform the specific act required | The court may compel the officer to act, but cannot dictate the substance of the decision |
| Example | Recording a deed that satisfies all statutory requirements; certifying an election result that the canvassing rules require; issuing a license to an applicant who meets all statutory criteria | Deciding whether to issue a discretionary permit; sentencing within a permitted range; granting or denying a discretionary benefit |
| Important caveat | Even purely ministerial duties may have prerequisites; the relator must establish that all conditions precedent have been satisfied | Mandamus may still issue to compel an officer to exercise discretion (i.e., to act at all), even where the officer cannot be told what to decide |
The Missouri writ retains a recognizably wide field of application. In contemporary practice it is most often seen in five recurring contexts.
A Missouri state court has no jurisdiction to mandamus a federal officer or compel a federal agency to act. If your delay is at USCIS, the State Department, or any other federal body, the right vehicle is a federal writ of mandamus under 28 U.S.C. § 1361 or an APA unreasonable-delay claim under 5 U.S.C. § 706(1), filed in the United States District Court — the Eastern or Western District of Missouri, depending on venue. My federal immigration mandamus practice is covered separately on the main pages of this site.
One: confusing "compel the exercise of discretion" with "compel a particular result." Missouri courts will mandamus a discretionary officer to act, but will not tell the officer what to decide. A petition that asks the court to direct a specific outcome on a discretionary matter is asking for relief the court will not grant.
Two: under-pleading the conditions precedent. Even a plain ministerial duty has prerequisites — the application must be complete, the fees must be paid, the statutory triggers must have occurred. Missouri courts deny mandamus petitions that fail to establish, with specificity, that every condition precedent to the officer's duty has been satisfied.
Three: filing in the wrong level of court. Concurrent original jurisdiction does not mean indifference about the choice of court. The Missouri Supreme Court tends to grant original mandamus only in matters of significant statewide importance; the courts of appeals handle most trial-court mandamus; the circuit courts handle most local-officer mandamus. Filing in the wrong court invites dismissal or transfer.
Of the four jurisdictions discussed on this site, Missouri presents the writ in its most traditional form. Anyone who studied mandamus from a treatise written in the early twentieth century will recognize the procedural shape immediately. I am admitted to the Missouri Bar but this page is general background, not legal advice on any specific case.
My commercial practice is federal immigration mandamus — compelling USCIS and the Department of State to act on unreasonably delayed applications. If you are looking at a USCIS delay and want a case evaluation, I am admitted in Missouri and litigate in federal district courts nationwide.
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