AIUI, the ruling in Illinois v. Gates was that “totality of circumstances applies,” which is that if the cops have an anonymous tipster plus some information that corroborates the tip, then they have probable cause to proceed with a warrant. But does this mean that if the tipster is known and verified (not anonymous,) they do not need corroborating information?
It would depend on whether the tipster is trustworthy and likely to know what they are saying is true.
I assume if the tipster is know, the police would have to attest to their reliability as a tipster. I.e. “this person has provided us with tips about such activities on several occasions in the past that have proven to be true.”
IANAL but the basic point is the judge has to be persuaded that there is probably cause.