MO Rev Stat § 544.155 (2021)
2021 Missouri Revised Statutes|Title XXXVII - Criminal Procedure|Chapter 544 - Arrest, Examination, Commitment and Bail|Section 544.155 - Uniform fresh pursuit law.

Effective - 28 Aug 1996   544.155. Uniform fresh pursuit law. — 1. Any member of a duly organized state, county, or municipal peace unit of another state of the United States who enters this state in fresh pursuit, and continues within this state in such fresh pursuit, of a person in order to arrest such person on the ground that such person is believed to have committed a felony or the crime of driving while intoxicated or driving with excessive blood alcohol content in such other state, shall have the same authority to arrest and hold such person in custody, as has any member of any duly organized state, county, or municipal peace unit of this state, to arrest and hold in custody a person on the ground that such person is believed to have committed a felony or the crime of driving while intoxicated or driving with excessive blood alcohol content in this state; provided, the rights extended by this subsection shall be extended only to those states granting these same rights to peace officers of this state who may be in fresh pursuit of suspected criminals in such reciprocating states.  2. If an arrest is made in this state by an officer of another state in accordance with the provisions of subsection 1 of this section, the arresting officer shall, without unnecessary delay, take the person arrested before a judge of a court of competent jurisdiction in the county in which the arrest was made, who shall conduct a hearing for the purpose of determining the lawfulness of the arrest. If the judge determines that the arrest was lawful, the judge shall order the person arrested to await, for a reasonable time, the issuance of an extradition warrant by the governor of this state, or admit such person to bail for such purpose. If the judge determines that the arrest was unlawful the judge shall discharge the person arrested.  3. Subsection 1 of this section shall not be construed so as to make unlawful any arrest in this state which would otherwise be lawful.  4. For the purpose of this section, the word "state" includes the District of Columbia.  5. The term "fresh pursuit", as used in this section, includes fresh pursuit as defined by the common law, and also the pursuit of a person who has committed a felony or the crime of driving while intoxicated or driving with excessive blood alcohol content or who is reasonably suspected of having committed a felony or the crime of driving while intoxicated or driving with excessive blood alcohol content. It shall also include the pursuit of a person suspected of having committed a supposed felony or the crime of driving while intoxicated or driving with excessive blood alcohol content, though no felony or the crime of driving while intoxicated or driving with excessive blood alcohol content has actually been committed, if there is reasonable ground for believing that a felony or the crime of driving while intoxicated or driving with excessive blood alcohol content has been committed. Fresh pursuit, as used therein, shall not necessarily imply instant pursuit, but pursuit without unreasonable delay.  6. This section may be cited as the "Uniform Law on Fresh Pursuit". ­­-------- (L. 1951 p. 456 §§ 1 to 6, A.L. 1996 S.B. 850)