# Federal Rules of Evidence/Judicial Notice

Article II of the Federal Rules of Evidence deals with judicial notice.

## Rule 201. Judicial Notice of Adjudicative Facts

    (a) Scope of rule. This rule governs only judicial notice of adjudicative facts.
    (b) Kinds of facts. A judicially noticed fact must be one not subject to reasonable dispute in that it is either (1) generally known within the territorial jurisdiction of the trial court or (2) capable of accurate and ready determination by resort to sources whose accuracy cannot reasonably be questioned.
Judicial notice is a very simple way to introduce a fact as evidence, but it is not frequently invoked.
The best-known example of judicial notice comes from the 1858 trial of "Duff" Armstrong, who was charged with murder and defended by Abraham Lincoln, then a Chicago railroad lawyer. An eyewitness claimed that Armstrong was able to see the victim in the moonlight. Lincoln produced a copy of the Farmers' Almanac, and asked the judge to take judicial notice that the moon was too low in the sky to produce moonlight on the night in question. The judge agreed, and Armstrong was acquitted.
Judicial notice may be based on "sources whose accuracy cannot reasonably be questioned," such as Lincoln's almanac. Judicial notice can also be based on local general knowledge. A lawyer trying a case in New York may ask the judge to take judicial notice that the East River is located between Manhattan and Brooklyn, or that the Empire State Building is the tallest building in the city. In such a case, no extrinsic evidence would be necessary. However, if the New York lawyer wanted the judge to take judicial notice that the river is forty-five feet deep, or that Minneapolis is located west of St. Paul, the lawyer would probably need extrinsic evidence.
    (c) When discretionary. A court may take judicial notice, whether requested or not.
Rule 201(c) is often implied when dealing with the validity of scientific tests. "Radar guns" are a common example. When they were first introduced to measure the speed of cars, many judges would require attorneys to establish the validity of their readings before the readings could be considered as substantive evidence. Today, most judges take judicial notice of the reliability of these readings whether counsel asks for it or not, since radar gun evidence is common in the courtroom. Opposing counsel can object, but judges need not obtain evidence to overrule the objection.
    (d) When mandatory. A court shall take judicial notice if requested by a party and supplied with the necessary information.
Note that Rule 201(d) does not mean that all requests for judicial notice will be granted. Any judicial notice must be of a fact that falls under Rule 201(b). The judge may (and legally, should) refuse to take judicial notice of any fact that is not generally known or readily verifiable.
    (e) Opportunity to be heard. A party is entitled upon timely request to an opportunity to be heard as to the propriety of taking judicial notice and the tenor of the matter noticed. In the absence of prior notification, the request may be made after judicial notice has been taken.
    (f) Time of taking notice. Judicial notice may be taken at any stage of the proceeding.
    (g) Instructing jury. In a civil action or proceeding, the court shall instruct the jury to accept as conclusive any fact judicially noticed. In a criminal case, the court shall instruct the jury that it may, but is not required to, accept as conclusive any fact judicially noticed.
Rule 201(g) differentiates criminal cases from civil cases. Its practical effect is on the jury instructions that come near the end of the trial. In the Armstrong case above, the judge's instruction would be:
* "You may, but are not required to, accept as a fact that there was no moonlight on the night in question."
If Armstrong were a civil case (e.g., for wrongful death), the instruction would be:
* "You must accept as conclusively true the fact that there was no moonlight on the night in question."