Ex Post Facto is latin for “from after the action”.  The concept in Texas and across the United States refers to the fact that a person cannot be charged with a crime that was not written at the time the crime occurred.  If Amy murdered Fred on August 14th, and the legislators failed to pass a law that murder was illegal until August 15th, then Amy cannot be criminalized for her action because the law was written Ex Post Facto.

Latin for After the Fact

“If the Speed limit Goes Down Today to 40, You Cannot Get in Trouble for Your 60 MPH speed from Yesterday” By Mr. Ex Post Facto

You can imagine how dangerous a country is that does not use the Ex Post Facto Rule.  One day you could be engaged in an act you know to be totally legal, and the next you can be charged with a crime because someone got a law enacted against your previously legal act.  Inherent in the United States Criminal Justice System is the idea that people have the right to know what the rules are or else they should not be held accountable to them.  This very idea is mentioned in Section 1.02 of the Texas Penal Code (that people have a right to know the criminal laws)

Certainly, this Ex Post Facto concept can be used as a defense against a criminal charged with a crime when it was unclear the act was a crime on the date the accused criminal engaged in the act.

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Similar to the ex post facto defense is the concept that a law was written in such poor form that a person cannot possibly know what the law prohibits.  For instance, a law that states: “No person shall do any wrongful thing against their mother” would be a law that is too vague to enforce.  What is “wrongful”?  What parties will constitute a mother?– will this include an adoptive mother, a step mother?  What is the meaning of against?  You see, the legislators have to go to great lengths to prevent laws that are void for vagueness as such laws are equally egregious as laws that are written after the commission of the stated crime.


Example 1 -Ex Post Facto

In the case of State v. Haney, a person was charged with unlawfully dispensing PHENMETRAZINE. This particular drug was not listed as an illegal drug for the Controlled Substance Act.  Despite the fact that the drug may have been dangerous, the legislators did not cover it, so the Defendant, Haney, could not be successfully prosecuted for this offense.

Example 2- No Law Against the Act

A Defendant was charged with Breach of the Peace.  While this sounds like a crime, no law in Texas was ever written that made it a crime to breach the peace, thus the case was dismissed.

Countries with Ex Post Facto Law (May be Called Something Else but Uses the Same or similar concept)

  • Brazil
  • Canada
  • Finland
  • Germany
  • India
  • Indonesia
  • Iran
  • Ireland
  • Italy
  • Japan
  • New Zealand
  • Norway
  • Pakistan
  • Russia
  • South Africa
  • Turkey

Countries Without Ex Post Facto Rule

  • Australia
  • Lithuania

Texas Version of the Ex Post Facto Law

§ 1.03. EFFECT OF CODE. (a) Conduct does not constitute an offense unless it is defined as an offense by statute, municipal ordinance, order of a county commissioners court, or rule authorized by and lawfully adopted under a statute. (b) The provisions of Titles 1, 2, and 3 apply to offenses defined by other laws, unless the statute defining the offense provides otherwise; however, the punishment affixed to an offense defined outside this code shall be applicable unless the punishment is classified in accordance with this code. (c) This code does not bar, suspend, or otherwise affect a right or liability to damages, penalty, forfeiture, or other remedy authorized by law to be recovered or enforced in a civil suit for conduct this code defines as an offense, and the civil injury is not merged in the offense. Acts 1973, 63rd Leg., p. 883, ch. 399, § 1, eff. Jan. 1, 1974. Amended by Acts 1993, 73rd Leg., ch. 900, § 1.01, eff. Sept. 1, 1994.

Ex Post Facto Resource

Case Talking About Ex Post Facto