Inevitable Discovery

Inevitable Discovery

The independent source doctrine admits evidence that the government actually obtained through a lawful channel. The inevitable discovery exception goes one step further. It admits evidence the government obtained unlawfully, on proof that lawful means would ultimately have produced the same evidence anyway. In Nix v. Williams the Court recognized the exception and held that tainted evidence comes in when the prosecution establishes by a preponderance of the evidence that the information ultimately or inevitably would have been discovered by lawful means.¹ This section begins with the facts of that case, because the exception is easiest to grasp as a description of what a search party was already doing when the police violated the Constitution.

A ten-year-old girl disappeared from a YMCA in Des Moines, Iowa, on Christmas Eve of 1968, and Robert Williams, who had recently escaped from a mental hospital, was seen leaving the building with her.² Police organized a search involving about 200 volunteers. Williams was arrested in Davenport and, on the drive back to Des Moines, responded to a detective's remarks that the body should be found before it snowed and that her parents were entitled to a Christian burial by leading the officers to it.³ Those statements were obtained in violation of Williams's Sixth Amendment right to counsel, and the Court reversed his first conviction on that ground in Brewer v. Williams.⁴ The violation was of the right to counsel, so Nix also shows that the fruits doctrine and its exceptions reach beyond searches and seizures; the Court has applied the doctrine to Sixth and Fifth Amendment violations as well.⁵

At the retrial the prosecution did not offer the statements. It offered the condition of the body, articles found with it, and the autopsy results, and it defended their admission with testimony from members of the search team.⁶ The search area had been divided into grids, and the teams had been told to check roads, abandoned farm buildings, and every other place a body could be hidden. One team was within a couple of miles of the body when Williams led the police to it, and testimony established that, given the weather and the number of searchers, the body would have been found within hours or at most a few days.⁷ The trial court admitted the evidence on the ground that it would have been discovered anyway, and the Iowa Supreme Court affirmed.⁸ The Eighth Circuit then assumed that an inevitable discovery exception exists but held that the State had not met a further requirement, proof that the police did not act in bad faith, and the Supreme Court reversed.⁹

The Court rested the exception on the same logic that supports independent source, and that logic has two edges. Exclusion exists to deter police from violating constitutional protections, so the prosecution is not to be left in a better position than it would have occupied had no illegality occurred. The same balance forbids leaving the prosecution in a worse position simply because of an earlier police error.¹⁰ Evidence that lawful means would inevitably have uncovered falls on the second edge. The police would have obtained it had no misconduct taken place, so the violation gave the government nothing to profit from, and suppression would hand the defendant a windfall while deterring no one. In that situation the Court said the deterrence rationale has so little basis that the evidence should be received, because anything less "would reject logic, experience, and common sense."¹¹ The later decision in Murray confirmed the lineage, explaining that Nix assumes the validity of independent source: if tainted evidence would be admissible when in fact discovered through an independent source, it should likewise be admissible if it inevitably would have been discovered.¹²

Because inevitable discovery is the hypothetical counterpart of independent source, the two doctrines answer different questions. Independent source asks what the officers in fact did, meaning whether a lawful channel actually delivered the evidence. Inevitable discovery asks what lawful investigation would have produced, so the prosecution's proof is a prediction.¹³ A prediction invites speculation, and the exception carries its own discipline against that. The lawful route must be one that was already under way, or would have been pursued, whether or not the violation occurred, so that the evidence would have been found despite the unlawful conduct and independently of it, and not merely in the absence of it.¹⁴ A dissenting opinion in Hudson v. Michigan used Nix itself to mark the line: the volunteer search was an ongoing lawful effort that would have found the body whether or not the Sixth Amendment violation had occurred.¹⁵

The burden and the standard of proof follow from that discipline. The prosecution carries the burden, and the standard is a preponderance of the evidence, meaning the prosecution must show that it is more likely than not that lawful means would have produced the evidence.¹⁶ Requiring actual proof about the lawful investigation, such as the grid assignments, the positions of the teams, and the weather, keeps the exception honest. A bare assertion that someone might eventually have stumbled on the evidence says nothing about what lawful investigation would have done. A separate opinion in Nix, which declined to join the Court's judgment, would have demanded clear and convincing evidence on the ground that the hypothetical finding differs in kind from the factual finding that precedes the independent source rule, but the standard the Court adopted is preponderance.¹⁷

The same discipline explains the most common error on this issue. Students lose points when they treat the fact that officers could have obtained a warrant as proof that discovery was inevitable. The government cannot avoid suppression of evidence seized without a warrant, or under a defective one, simply by showing that it could have obtained a valid warrant had it asked for one, because inevitable discovery looks to what lawful means would have done, and an available route that no one was pursuing shows only what could have happened.¹⁸ The doctrine is therefore best run as a sequence of questions about the lawful path.

The fourth step marks the last feature of the exception, which is an omission. The Court of Appeals had treated proof of police good faith as a threshold element, and the Supreme Court rejected that requirement, reading the exploitation question from Wong Sun as leaving no room for it.¹⁹ The reason lies in what the exception asks. The only question is what lawful means would have produced, and an officer's state of mind does not change whether a search team would have reached the next grid square. A bad-faith bar would also give the defendant a windfall in precisely the cases where the violation gave the government no advantage, and it would leave the prosecution in the worse position that this branch of the fruits doctrine forbids. The questioning in Nix was a clear constitutional violation, yet the exception applied, because the fact that lawful means would have found the body shows that the government did not ultimately exploit its unconstitutional conduct.²⁰

Nix states the federal rule, and a state court applying its own constitution may refuse the exception. The Washington Supreme Court, for example, has held the inevitable discovery doctrine incompatible with its state constitution, reasoning that the state's privacy provision contains no express limitations and requires a remedy whenever the right is unreasonably violated.²¹ A fact pattern set in a state with such a ruling would therefore change the answer even where the federal analysis favors admission.