The erosion of the Fourth Amendment nearing completion?

The Court today issued the published opinion in United States v. Fofana. 12a0018p.06  One paragraph from this opinion provides most of the story:

There is a difference between evidence that the Government obtains because of knowledge illegally acquired, and evidence properly in the Government’s possession that it learns the relevance of because of knowledge illegally acquired.  It may be that the latter must be suppressed in some cases.  But in the context of the present case, bank records and other evidence that the Government obtained independently of the airport search do not have to be suppressed on account of the unconstitutionality of that search, merely because the relevance or usefulness of that evidence became apparent because of the search.

The Court creates in this decision a new exception to the fruit of the poisonous tree doctrine, holding that where there is an independent basis for a police officer to obtain evidence, that illegally obtained evidence which shows the relevance of the illegality of that evidence does not require suppression. 

In her dissent, Judge Moore found that the establishment of connection between offender and the evidence is crucial - if that link comes only through the use of otherwise suppressible evidence, then it cannot be used to provide that link.

The majority opinion spent much of its focus on the use of the exclusionary rule versus public policy - the Court found that there must be a balance between the deterrent rationale of the exclusionary rule and "truth seeking function of the courts", and that in this case, the deterrent effect would be minimal.