MO Rev Stat § 491.050 (2021)
2021 Missouri Revised Statutes|Title XXXIII - Evidence and Legal Advertisements|Chapter 491 - Witnesses|Section 491.050 - Convicts competent witnesses — convictions and certain pleas may be proved to affect credibility.

Effective - 28 Aug 1981   491.050. Convicts competent witnesses — convictions and certain pleas may be proved to affect credibility. — Any person who has been convicted of a crime is, notwithstanding, a competent witness; however, any prior criminal convictions may be proved to affect his credibility in a civil or criminal case and, further, any prior pleas of guilty, pleas of nolo contendere, and findings of guilty may be proved to affect his credibility in a criminal case. Such proof may be either by the record or by his own cross-examination, upon which he must answer any question relevant to that inquiry, and the party cross-examining shall not be concluded by his answer. ­­-------- (RSMo 1939 § 1916, A.L. 1981 H.B. 554)  Prior revisions: 1929 § 1752; 1919 § 5439; 1909 § 6383  (1971) Trial court erred in refusing to permit defendant in prosecution for robbery to inquire on cross-examination of witness whether or not he had been convicted of a crime since witness was the only witness who implicated defendant in the robbery. State v. Myer (Mo.), 473 S.W.2d 374. (1971) Questions directed to the defendant on trial for murder implying he was guilty not only of moral misconduct but of offenses connected with prostitution, including being a pimp, were immaterial, irrelevant and designedly and manifestly prejudiced the only remedy for which was a new trial. State v. Taylor (Mo.), 473 S.W.2d 385. (1971) Refusal by trial court to allow defendant to impeach state's four principal witnesses, adults at time of trial, on the basis that each had previously committed an offense while a juvenile, which would have been a crime if committed by an adult, was upheld. State v. Williams (Mo.), 473 S.W.2d 388. (1974) It is reversible error for a party or a witness to be impeached by showing an arrest even where he has testified about previous convictions. State v. Massa (A.), 512 S.W.2d 912. (1974) This section confers an absolute right to cross-examine as to conviction of a crime solely to affect credibility. Forbis v. Associated Wholesale Grocers, Inc. (A.), 513 S.W.2d 760. (1976) Held, cross-examination on collateral matters (except for a criminal conviction) binds the examiner to the answer given. State v. Diamond (A.), 532 S.W.2d 873. (1976) Overruling defendant's pretrial motion, seeking to limit state's cross-examination concerning his previous convictions in event he should decide to take the stand thereby depriving him of right to make intelligent decision before trial as to whether he could take the stand, was not error. State v. Tolliver (Mo.), 544 S.W.2d 565. (1978) It is permissible to impeach the credibility of a witness by showing pardoned convictions. Durham v. State (A.), 571 S.W.2d 673. (1985) Held, that a witness can be impeached by his prior guilty plea, even though he had completed probation under a suspended imposition of sentence. State v. Brooks (A.), 694 S.W.2d 851. (1995) "Conviction" does not include finding of guilty when imposition of sentence was suspended. M.A.B. v. Nicely, 909 S.W.2d 669 (Mo.banc).