Thompson v. Missour

171 U.S. 380 (1898).

Facts

Thompson (D) was indicted for the murder of Cunningham. At trial, handwriting samples were admitted over the objection of D. D denied that he was connected with the writings to the organist of the church. Those letters to the organist were used to compare D's writing to that of the samples collected by the police. D was convicted, but that was reversed because of the use of the letters from the church organist to compare handwriting. The legislature of Missouri then passed a law that allowed the admission of handwriting samples for comparison. D was tried a second time. The letters were admitted into evidence over D's objection. D was convicted and appealed; the law is ex post facto.