The phrase "substantial basis" is inherently deferential. Our inquiry is not whether we, as judges, can conclude as a matter of law that probable cause actually existed. We may conduct an independent analysis of the content of the affidavit, but we need only see enough to persuade us that there was a substantial basis for the magistrate's conclusion. This is probable cause at least once removed; i.e., deference is built into Gates' wording of the "substantial basis" standard.The KSC went on to apply this standard and agreed with Judge Caplinger, who had dissented from the COA decision, that the affidavit was insufficient:
Even when we view the affidavit at the heart of this case in the context of the totality of the circumstances and keep in mind our Gates obligation of deference to the issuing magistrate, we simply cannot conclude that the magistrate had enough before him to establish a substantial basis for the existence of probable cause. The parts are weak, and the whole is not greater than the sum of them. Although it is possible that the concerned citizens were not anonymous to the police, or, if so, that they were nevertheless worthy of trust and their complaints accurate and corroborated, the affidavit did not say so. Although the two visitors to Hicks' home may have had more recent drug abuse and distribution histories and more numerous or more frequent visitors with similar pasts may have congregated at the house, the affidavit did not say so. Although the affiant may have based his assertion that the trash pulls came from the normal place Hicks left his trash for pickup on his own or others' observation of Hicks' behavior or on indices of residency in the bags, the affidavit did not say so. With none of this information, the affidavit did not provide a substantial basis for a fair probability that evidence of crime would be found in Hicks' residence.The KSC noted that the prosecutor had not argued that the Leon good-faith exception could apply to save this search and therefore declined to consider that possibility.
A good day for Judge Caplinger, who dissented in two COA decisions, which were ultimately overruled by the KSC!