In the United States is it commonly accepted by judges to issue search warrants based on anonymous tips or unidentified informants?

The reason I ask is that the 4th ammendment to the US Constitution says that warrants shall only be issued on probable cause supported by oath, and a tip by an anonymous person does not constitute an oath.

  • 1
    An oath by an officer that he has such information is an oath (or affirmation).
    – user6726
    Apr 17, 2017 at 0:38
  • The "oath or affirmation" can be from the officer or staff making the application; they affirm that their reasonable cause stems from information obtained, and that this information is reliable (regardless of its provider's anonymity).
    – user4657
    Apr 17, 2017 at 0:45
  • An oath by someone other than the one providing the evidence does not "support" the evidence. If person A says that they have witnessed something, then some other person B who has not witnessed it cannot "support" it. Only the person who witnessed the evidence can claim that it is true by oath.
    – Cicero
    Apr 17, 2017 at 1:05
  • The 4th does not require a person who witnessed the evidence to make a oath. Maybe you can argue that that is how it should be interpreted, but that is not how it is interpreted. Is your question really a factual one about frequency of warrants based on informants (who do not take oaths before judges), or is that just a cover for asking how they dare to issue warrants without talking to the witness. Or: is the question about what constitutes probably cause? Illinois v. Gates, 462 U.S. 213, for example.
    – user6726
    Apr 17, 2017 at 1:49
  • There is a rather elaborate case law governing anonymous informants as a basis for search warrants. If I can find it, I will post an answer, but since I don't practice in that area it isn't something I know right off. Certainly, not everyone in a chain of hearsay needs to be sworn in an affidavit supporting a warrant, whether or not the unsworn informant is anonymous, and indeed, it would be exceedingly rare that this was the case. Typically a cop swears to an affidavit about what he has heard and seen, much of which is hearsay, rather than from personal knowledge.
    – ohwilleke
    Apr 17, 2017 at 1:54

1 Answer 1


Yes. This was most recently clarified in Navarette v. California 572 U.S. ___ (2014).

A seizure can be deemed reasonable based on an anonymous tip. The reasonableness analysis is the standard "totality of the circumstances" test and the anonymous tip would usually need to have indicia of reliability.

  • 1
    Some of the other leading cases that analyze the question in depth that provides a sense of when an anonymous tip is and is not permissible are Spinelli . United States, 393 U.S. 410 (1969) and Illinois v. Gates, 462 U.S. 213 (1983), although subsequent cases have made it on the whole easier to use an anonymous tip.
    – ohwilleke
    Apr 22, 2017 at 23:26

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .