Definitions[]
Criminal law[]
Probable cause is
| “ | [a] reasonable belief that a crime has been committed and that the person to be apprehended committed it.[1] | ” |
Foreign intelligence[]
Probable cause
| “ | exists when facts and circumstances within the applicant's knowledge and of which he/she has reasonably trustworthy information are sufficient to warrant a person of reasonable caution to believe that the proposed target of the surveillance is an agent of a foreign power.[2] | ” |
Fourth Amendment[]
Probable cause is
| “ | [a] reasonable belief that a crime has been committed and that the person, property, or evidence sought in connection with the crime is located in the place or on the person to be searched.[3] | ” |
Overview[]
As a general rule, the Fourth Amendment requires the government to demonstrate probable cause and obtain a warrant (unless a recognized warrant exception applies) before conducting a search.
Probable cause is "a fluid concept — turning on the assessment of probabilities in particular factual contexts."[4] For example, for issuance of a search warrant, probable cause requires an issuing magistrate to determine, based on specific evidence, whether there exists "a fair probability that contraband or evidence of a crime will be found in a particular place."[5]
Surveillance[]
Probable cause exists when facts and circumstances within the applicant's knowledge and of which he/she has reasonably trustworthy information are sufficient to warrant a person of reasonable caution to believe that the proposed target of the surveillance is an agent of a foreign power.[6]
References[]
- ↑ Office of Counterintelligence (DXC), Defense CI & HUMINT Center, Defense Intelligence Agency, "Terms and Definitions of Interest for DoD Counterintelligence Professional," at GL-142 (May 2, 2011) (full-text).
- ↑ See generally United States v. Cavanagh, 807 F.2d 787 (9th Cir. 1987) (full-text).
- ↑ Office of Counterintelligence (DXC), Defense CI & HUMINT Center, Defense Intelligence Agency, "Terms and Definitions of Interest for DoD Counterintelligence Professional," at GL-142 (May 2, 2011) (full-text).
- ↑ Illinois v. Gates, 462 U.S. 213, 238 (1983) (full-text).
- ↑ Id. at 238.
- ↑ See generally United States v. Cavanagh, 807 F.2d 787 (9th Cir. 1987) (full-text).