What is the test for probable cause when relying on information from an untested informant?

While information from an untested informant, standing alone, is insufficient for probable cause, it can rise to the level of probable cause when supplemented by sufficient corroboration through independent police work. Illinois v. Gates, 462 U.S. 213, 244-44 (1983). And, statements against penal interest add to the informant's indicia of reliability, because individuals do not blithely admit to criminal activity. United States v. Dozier, 844 F.2d 701, 706-07 (9th Cir.), cert. denied, 488 U.S. 927 (1988).