Legal Definitions - post facto

post facto

This Latin term translates to "after the fact." It describes an action, event, or decision that occurs subsequent to an earlier, relevant event.

While "post facto" broadly means "after the fact," in legal contexts, it is most commonly encountered as part of the phrase "ex post facto," which refers specifically to a law that retroactively changes the legal consequences of actions committed before the law's enactment. However, "post facto" on its own simply denotes something happening later in time.

Here are some examples illustrating the concept of "post facto":

• Example 1: Incident Investigation

  After a serious workplace accident, a company initiates a comprehensive safety investigation to determine the cause and prevent future occurrences. This investigation includes interviewing witnesses, reviewing equipment logs, and analyzing the accident scene.

  Explanation: The safety investigation is a post facto action because it takes place entirely after the accident has already happened. Its purpose is to understand and respond to an event that has already occurred.

• Example 2: Policy Implementation

  Following a series of complaints from residents about excessive noise, a local city council passes a new ordinance restricting loud activities after 10 PM. The ordinance takes effect the following month.

  Explanation: The city council's decision to pass the new noise ordinance is a post facto response. It was enacted after the complaints (the "fact") prompted the need for new regulations, addressing an existing problem.

• Example 3: Remedial Action

  A software company discovers a critical security vulnerability in its widely used application. It then releases a patch to all users to fix the flaw.

  Explanation: The release of the software patch is a post facto remedial action. It is developed and distributed after the vulnerability (the "fact") was identified, aiming to correct a problem that already exists within the software.