Nix v. Williams

Justices Brennan and Marshall offered a joint dissenting opinion arguing that the Court undermined the exclusionary rule by blurring the difference between the inevitable discovery doctrine and the independent source exception. The independent source doctrine, they stressed, applies only to evidence that was, in fact, found. Brennan and Marshall cautioned that allowing evidence to be admitted, which would have inevitably been discovered, could potentially impose on constitutionally protected rights. They therefore argue that the inevitable discovery exclusion, though sound in principle, should be subjected to a "heightened burden of proof."