Also known as: two part test · two-part tests · two parts test · two-prong test · bipartite test
Written by attorneys · grounded in primary & secondary sources — see below
A structured analytical framework requiring a decision-maker to evaluate two distinct conditions or prongs before reaching a conclusion.
Tiana Tan formed Ortiz Catering Inc. with no meaningful capital and used a single bank account for both personal groceries and corporate expenses while advertising under her own name. After the company failed to pay trade creditors, the court examined whether the entity was her alter ego and whether respecting the form would promote injustice. Finding both prongs satisfied, the court disregarded the corporate entity and imposed personal liability on Tan.
Talia Torres spoke on a cordless phone from inside her home about personal matters she believed no one else could hear. Government agents intercepted the call without a warrant. The court first asked whether Torres exhibited an actual expectation of privacy and then whether society would recognize that expectation as reasonable, concluding that the interception constituted a search.
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Trevor Tate challenged a federal statute authorizing civil commitment of sexually dangerous prisoners after their sentences ended. The court first determined whether the statute pursued a legitimate end within Congress's enumerated powers and then assessed whether the means were plainly adapted to that end. Finding both requirements met, the court upheld the statute.
Tanya Tang was convicted after her lawyer presented almost no mitigating evidence at sentencing. The court first examined whether counsel's performance fell below prevailing professional norms and then determined whether the deficient performance created a reasonable probability of a different outcome. Both prongs established, the court found ineffective assistance.
Thaddeus Tran sought to register a mark that an examiner found likely to disparage a national symbol. The examiner first considered the likely meaning of the mark in context and then evaluated whether that meaning would bring the symbol into contempt or disrepute. Both steps led to refusal of registration.
Taliah Tang rejected a favorable plea offer after her lawyer gave deficient advice about sentencing exposure. The court first confirmed deficient performance and then assessed whether there was a reasonable probability she would have accepted the plea but for the advice. Both elements satisfied, the court found prejudice from the lost opportunity.
A plaintiff must demonstrate both unity of interest between the shareholder and the corporation and that respecting the corporate form would sanction fraud or promote injustice. Undercapitalization, commingling of funds, and failure to observe formalities help establish the first prong. Allowing a shell entity to shield the shareholder from legitimate creditor claims satisfies the second prong.
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The defendant must first show that counsel's performance was deficient under prevailing professional norms. The defendant must then show that the deficient performance prejudiced the defense by creating a reasonable probability of a different outcome. Both elements are required. Deficiency alone does not warrant relief.
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A person must first exhibit an actual subjective expectation of privacy. That expectation must then be one that society is prepared to recognize as reasonable. Information knowingly exposed to the public fails the test, while efforts to preserve privacy may succeed even in public areas.
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…Concurring opinions Concurring in part and dissenting in part — Justice Brennan Justice Brennan agreed that the two-prong test was appropriate but disagreed with the majority's application of the prejudice prong in capital cases. He would require a somewhat different showing of prejudice in the capital sentencing…