The trial court suppressed the first statement because it was given before the Miranda warnings, but admitted the second. Seibert was convicted of second-degree murder. The Supreme Court granted certiorari to resolve a split among the Circuit Courts of Appeal on this issue.
Souter, writing for the plurality, focused on the actual effectiveness of Miranda warnings given after an earlier unwarned confession. Just giving the warnings is not necessarily good enough. Instead, a court must ask, "Could the warnings effectively advise the suspect that he had a real choice about giving an admissible statement at that juncture? Could they reasonably convey that he could choose to stop talking even if he had talked earlier?"
The plurality opinion gives some guidance on when an intermediate warning should be considered to be effective. Such a warning is likely to mislead a defendant about his rights when it is made "in the midst of coordinated and continuing interrogation." Courts should therefore consider "the completeness and detail of the questions and answers in the first round of interrogation, the overlapping content of the two statements, the timing and setting of the first and the second, the continuity of police personnel, and the degree to which the interrogator's questions treated the second round as continuous with the first."
Justice Breyer concurred. He set forth a different test for whether the second confession should be admissible: "Courts should exclude the "fruit" of the initial unwarned questioning unless the failure to warn was in good faith." The term "fruit" refers to the fruit of the poisonous tree doctrine, which provides that in criminal trials, courts may not admit evidence obtained as an indirect result of a search that violated the Fourth Amendment. Justice Breyer's proposed rule would extend that doctrine to evidence obtained as an indirect result of an interrogation that violated the Fifth Amendment. Although this test was different from Justice Souter's, Breyer also joined with the Souter's plurality opinion because he thought that the two tests would yield the same result in practice.
Justice Kennedy also concurred, and proposed yet another test. He wrote that he "would apply a narrower test applicable only in the infrequent case, such as we have here, in which the two-step interrogation technique was used in a calculated way to undermine the Miranda warning." If a two-step procedure was deliberately used, the subsequent statement would be inadmissible unless the police "cured" the problem by taking measures that would enable the suspect to distinguish the first interrogation from the second "and appreciate that the interrogation has taken a new turn." Kennedy suggested that a long break between the two interrogations would usually be sufficient, as would an explanation to the suspect that the first statement would probably be inadmissible in court.
The dissent would thus have allowed police to continue to use the question-first, warn-later approach, so long as they could show that the first confession was voluntary and that the "taint" of the first confession had worn off.
Seibert was a split decision. The general rule is that when there is no majority opinion in a Supreme Court case, the narrowest rationale agreed upon by at least five Justices controls. But lower courts have disagreed about what that rationale is in Seibert: some have adopted the "effects" test from the plurality opinion; others have adopted the "intent" test from Kennedy's opinion. As Gerald Uelmen has written, "The fractured opinions" in Seibert "have left lower courts in limbo." Midstream Miranda Warnings After Seibert, Champion, July, 2005.
According to Justice Souter's opinion, the two-step interrogation practice was becoming increasingly popular among police departments. Given the confusion about Seibert's meaning, it remains to be seen whether that changes.
In State v. O’Neill (N.J. Super. Crt. App. Div. 2006) (case #14-2-5143) the New Jersey Appellate Court held that the defendant's statements given to police after a so-called, "question-first, warn-later" interrogation were admissible. From reading the NJ Court's opinion, the court bases their ruling on the length of time between the first, non-mirandized interrogation and the second, mirandized interrogation, which was about 1 hour and 15 minutes; that the questioning during the first interrogation were unrelated to the questioning during the second interrogation; that the statements that O'Neill made were different during the first and second interrogation; and that the first interrogation took place at one location (jail cell) while the second interrogation had taken place at another (patrol commander's office). In terms of Seibert, the NJ Appellate Court endorses the reasoning contained in the concurring opinion of Justice Kennedy.