What Are the Criteria Laid Out by the Totality of Circumstances Test for Probable Cause?
- The term "probable cause" is not defined in the U.S. Constitution, nor in the relevant federal statutes. Instead, probable cause is a concept defined by the courts to determine whether a search or seizure was justified. Essentially, a government officer has probable cause for a search or seizure if he has a good, logical reason to believe that wrongdoing is occurring or has occurred.
- Prior to the adoption of the "totality of the circumstances" test for probable cause, courts followed a two-pronged rule laid out by the U.S. Supreme Court in Aguilar v. Texas and Spinelli v. United States. To issue a search warrant under this test, an affidavit was needed which both established the basis of the informant's knowledge, and set forth enough facts to show that the informant was either truthful or reliable.
- In 1983, the U.S. Supreme Court issued its opinion in Illinois v. Gates, changing the landscape for determining probable cause. In Illinois v. Gates, the Supreme Court rejected the old two-prong test as too rigid. Instead, the Court held that a magistrate can issue a search warrant when, under the totality of the circumstances, "There is a fair probability that contraband or evidence of a crime will be found in a particular place." The Court emphasized that this brought these types of cases in line with the general rule for determining whether probable cause exists: now, in all types of cases, the totality of the circumstances determines whether probable cause is present.
- Courts considering whether the totality of the circumstances support probable cause can look at any factor that makes it more or less likely that contraband or illegal activity is present or has occurred. These include the factors that were a part of the old two-pronged test, as well as many others. Given particular weight is independent police work, which confirms or corroborates original information, or an informant's tip. Courts can even consider facts that would not be admissible as evidence in court, such as an anonymous letter.
