What is the legal test for probable cause?

"The test for probable cause is not reducible to 'precise definition or quantification.' [Citation.] 'Finely tuned standards such as proof beyond a reasonable doubt or by a preponderance of the evidence . . . have no place in the [probable-cause] decision.' [Citation.] All [the United States Supreme Court has] required is the kind of 'fair probability' on which 'reasonable and prudent [people,] not legal technicians, act.' [Citation.]" (Florida v. Harris (2013) 568 U.S. 237, 243-244 (Harris).)