- Defendant cannot be prosecuted for a prior act that was not a crime when it was committed, or be subjected to an increased punishment which was added after the offense was committed.
- Changes in rules of evidence and procedure, additional civil remedies, or new offense classifications used in future proceedings normally do not violate the ex post facto clause.
Unlike double jeopardy issues, which ordinarily involve questions of successive prosecutions or multiple punishments for the same offense, ex post facto issues typically arise when there has been a change in the law that potentially impacts the criminality of a prior act, or alters punishment for an offense already adjudicated. Specifically, the ex post facto provisions of the United States Constitution (Article 1, Section 9, Clause 3, with respect to federal laws, and Article 1, Section 10, with respect to state laws) and the North Carolina Constitution (Article 1, Section 16) prohibit:
- The enactment of a statute that makes criminal an act that was not a crime when it was committed;
- Changing the elements of an offense after it was committed and to the defendant’s disadvantage;
- Increasing the punishment for a crime after the act constituting the crime was committed (State v. Detter, 298 N.C. 604 (1979); and
- Eliminating a defense to a crime that existed when the crime was committed or altering the sufficiency of evidence to convict.
Changes in rules of evidence or criminal procedure generally do not violate ex post facto provisions. In re Stedman, 305 N.C. 92 (1982) (holding that statute allowing fingerprinting of juvenile after commission of offense did not violate ex post facto); Dobbert v. Florida, 432 U.S. 282 (1977); Hopt v. Utah, 110 U.S. 574 (1884); Thompson v. Missouri, 171 U.S. 380 (1898); but see Carmell v. Texas, 529 U.S. 513 (2000) (Texas statute violated ex post facto clause by eliminating corroboration-of-witness rule to convict defendant by testimony alone).
While ex post facto provisions only involve legislative enactments, the Fifth and Fourteenth Amendments also prohibit the retrospective application of other unforeseeable judicial modifications of criminal law to the detriment of a defendant. See State v. Vance, 328 N.C. 613 (1991) (abrogating year-and-a-day rule for murder prospectively only); State v. Barnes, 345 N.C. 184 (1997); State v. Robinson, 335 N.C. 146 (1993).
However, other modifications such as additional civil remedies for sex offenses or reclassification of prior offenses for use in future proceedings have been upheld against ex post facto challenges. See State v. Bowditch, 364 N.C. 335 (2010) (subjecting previously convicted defendants to new satellite-based monitoring requirements did not violate ex post facto laws, since SBM regulations were civil in nature); State v. Wolfe, 157 N.C. App. 22 (2003) (reclassification of a felony offense after it was committed so that it became a violent felony under the violent habitual offender statute did not violate the ex post facto clause); State v. Wiley, 355 N.C. 592 (2002) (change in law allowing prior juvenile murder adjudication to be counted as a prior violent felony conviction did not violate ex post facto); State v. Taylor, 349 N.C. 219 (1998), affirming per curiam, 128 N.C. App. 394 (1998) (not error to rely on prior juvenile conviction as aggravating factor in sentencing where that conviction was added as a qualifying prior subsequent to the conviction date); State v. Mason, 126 N.C. App. 318 (1997) (different classification of prior felonies at time of their commission than at time of violent habitual offender determination did not violate defendant's rights against ex post facto laws); State v. Todd, 313 N.C. 110 (1985) (enactment of habitual felon law did not violate ex post facto provisions); but see Stogner v. California, 539 U.S. 607 (2003) (Supreme Court ruled that legislation which extended the statute of limitations for certain kinds of sex offenses violated the ex post facto clause when it revived the prosecution of offenses that had already been barred by the prior version of the statute of limitations for those offenses).