That no ex post facto law, nor law impairing the obligation of contracts, or retrospective in its operation, or making any irrevocable grant of special privileges or immunities, can be enacted.

Source: Const. of 1875, Art II, § 15.

  (1953) Relation between Public School Retirement System of St. Louis and its members is contractual and § 169.515 of 1953 Act (H.B. 164) which required transfer of certain funds thereof to special fund to be used in making contributions to Federal Old Age and Survivors Insurance System for certain members thereof, held invalid as impairing the obligations of contract. Dictum: Section 169.510 of 1953 Act also void for same reason. State ex rel. Phillip v. Public School Retirement System, 364 Mo. 395, 262 S.W.2d 569.

  (1955) Section 556.285 which makes person convicted more than three times of larceny guilty of grand larceny on conviction of a subsequent larceny held valid against challenge based on the due process, equal protection and ex post facto provisions of the constitution. State v. King (Mo.), 275 S.W.2d 310.

  (1956) Where attorney's contract with insurance superintendent contemplated his payment out of funds recovered by litigation contrary to statute for payment of such compensation, a statute authorizing escheat of such recovered funds was, therefore, not violative of obligation of contract. Jacobs v. Leggett (Mo.), 295 S.W.2d 825.

  (1956) Provision authorizing pledge of on-street parking meter receipts for payment of revenue bonds issued to enable city to acquire off-street parking facilities held constitutional. Petition of City of Liberty (Mo.), 296 S.W.2d 117.

  (1958) Where definition of "habitual violator of traffic laws" authorizing suspension of driver's license was changed so as to include one convicted four times in two years rather than those convicted five times in one year, it applied to one convicted three times before the change was made and one time thereafter, and was not retrospective in violation of the constitution. Barbieri v. Morris (Mo.), 315 S.W.2d 711.

  (1958) Daughter adopted by testator's daughter in 1909 held to be entitled to share in distribution of remainder of trust estate to "lineal descendants" of testator under will executed in 1927 and where remainder which qualified adopted daughter as lineal descendant violative of §§ 10 and 13 of Art. I of the Constitution. Commerce Trust Co. v. Weed (Mo.), 318 S.W.2d 289.

  (1960) Provision of 1959 act authorizing the judge of the court to fix the punishment rather than a jury, upon establishment of prior offenses, held not to violate provision of Constitution prohibiting ex post facto laws. State v. Morton (Mo.), 338 S.W.2d 858.

  (1961) Proceedings under habitual criminal law in prosecution for homicide committed prior to effective date of amendment of the law did not result in violation of constitutional provision against ex post facto laws, nor deny defendant, due process and equal protection of laws, unconstitutionally deny him right to trial by jury on fact question of previous convictions, sentence and discharge therefrom. State v. Chamineak (Mo.), 343 S.W.2d 153.

  (1961) The rule of immunity of charities from suits for torts held not to be an irrevocable grant of special privileges or immunities for the reason that the grant of privileges prohibited are those granted to individuals and not to charities as a class. Schulte v. Missionaries of LaSalette Corp. of Mo. (Mo.), 352 S.W.2d 636.

  (1961) Fact that habitual criminal act was amended in 1959 would not make it inapplicable to an act committed prior to the effective date of that act or make it an ex post facto law within the meaning of the constitution. State v. Donnell (Mo.), 351 S.W.2d 775.

  (1962) Increase of benefits to previously retired members of State Employees Retirement System held void as an impairment of contract as to members not yet retired and as being retrospective as it affects retired members. State v. Missouri State Employees Retirement System (Mo.), 362 S.W.2d 571.

  (1971) Mandamus lay, under subsection 3 of § 206.120, to compel county court judges to dissolve a hospital district established in 1963 where no successful election on proposition to borrow money for any purpose had been conducted in the district within five years from its establishment although action was begun less than five years after the effective date of subsection 3 of § 206.120. State ex rel. Meyer v. Cobb (Mo.), 467 S.W.2d 854.

  (1986) Application of §§ 610.100 to 610.120, RSMo, to records kept before September 28, 1973, does not violate ban on ex post facto or retroactive law. Martin v. Schmalz, 713 S.W.2d 22 (Mo.App. 1986).

  (1993) Where § 370.362, RSMo, may impair contractual obligations of parties and is retrospective in operation, statute does not violate this constitution's or federal constitution's contract clause because it has significant and legitimate public purpose to remedy broad general, social or economic problem and enactment of section was proper exercise of inherent police power of state. Educational Employees Credit Union v. Mutual Guaranty Corporation, 821 F.Supp. 1294 (E.D. Mo.).

  (1993) Expiration of statutes of limitation for tort actions created vested right in favor of defendants to be free from suit; therefore, to extent that § 537.046, RSMo, authorizes causes of action that would have been barred under statutes of limitation in effect prior to effective date of § 537.600, RSMo, statute contravenes constitutional prohibition against retrospective laws. Doe v. Roman Catholic Diocese, 862 S.W.2d 338 (Mo. en banc).