Judicial Notice is a rule in the law of evidence that allows a fact to be introduced into evidence if the truth of that fact is so notorious or well known that it cannot be refuted. This is done upon the request of the party seeking to have the fact at issue determined by the court. Matters admitted under judicial notice are accepted without being formally introduced by a witness or other rule of evidence, and even if one party wishes to lead evidence to the contrary.

For example, in an insurance claim for spoiled food from the August 14, 2003 blackout in north-east North America, the plaintiff would not be required to call witnesses to prove that there was no way to get power to run their freezers during the period in question.

A famous example of the use of judicial notice was Abraham Lincoln's "Almanac Case", Illinois v. Armstrong (1858). When a witness claimed that the moon was directly overhead when he saw a murder, giving enough light to see clearly, Lincoln introduced an almanac into evidence to show that at the time in question, the moon was just above the horizon. The court accepted the information in the almanac despite evidence to the contrary from the witness.

Judicial notice in the Federal Rules of Evidence

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In the United States, Article II of the Federal Rules of Evidence ("FRE") address judicial notice in federal courts, and this article is widely copied by U.S. States. FRE 201(b)) permit judges to take judicial notice of two categories of facts:

1. Those that are "generally known within the territorial jurisdiction of the trial court" (e.g. locations of streets within the court's jurisdiction) or
2. Those that are "capable of accurate and ready determination by resort to sources whose accuracy cannot reasonably be questioned" (e.g. the day of the week on a certain date).

The FRE also notes that judicial notice may be permissive or mandatory. If it is permissive, then the court may choose to take judicial notice of the fact proferred, or may reject the request and require the party to introduce evidence in support of the point. If it is mandatory, then the court must take judicial notice of the fact proferred. Although the FRE does not expand upon the kinds of facts that would fall into one category or another, court cases, however, have determined that courts must take mandatory judicial notice of federal public laws and treaties, state public laws, and official regulations of both federal and local government agencies.

Judicial notice and the burden of proof

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The effect of the court taking judicial notice is different in civil and criminal trials. In a civil trial, the fact taken notice of is thereby conclusively proven. In the above example regarding the blackout, if the court were to take judicial notice of the fact that power was unavailable, the party opposing that finding would be prohibited from attempting to introduce evidence to prove otherwise.

In criminal trials, however, the defendant has the right to contest every fact that might tend to incriminate them. Therefore, the court taking judicial notice would simply allow the jury to make the finding that the court took notice of, but would not require this outcome, and would not prevent the defense from presenting evidence to rebut the noticed fact.

Judicial notice in foreign affairs

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Legal disputes about foreign affairs are generally settled by judicial notice by obtaining the information directly from the office of the Secretary of State (in the United States) or the Foreign Secretary (in the United Kingdom). For example, if a litigant in an extradition hearing attempted to argue that Israel was not a sovereign state, a statement from the Secretary of State that the U.S. recognized Israel as a sovereign state would settle the issue and no evidence could be led to the contrary.

Recently, Court of Appeal decisions regarding the legal rights of detainees of Guantanamo Bay took judicial notice of Cuba having no sovereignty over the U.S. naval base in that location despite claims by the United States government that it was Cuban territory and not subject to the application of United States law.

Federal courts and the courts of most jurisdictions have determined that matters of foreign law are subject to permissive judicial notice.

Evidence