Also known as: but-for · but for test · but-for test · but-for causation
Written by attorneys · grounded in primary & secondary sources — see below
A test for factual causation under which conduct qualifies as a cause of a result if the result would not have occurred without that conduct.
Marlon released livestock onto a highway after days of delusional fixation that the animals were government drones. Medical records confirmed worsening PTSD and dissociative episodes. The court applied the Durham rule and found that Marlon would not have committed the criminal mischief but for his mental disease. The offense therefore resulted from the condition and required acquittal.
LuxeLinea sued boutique owner Maria but named the wrong corporate defendant. Within the Rule 4(m) period the correct entity knew the suit would have been brought against it but for the mistaken identity. The amendment therefore related back under Rule 15(c).
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Eric skipped a required stability test on a drug batch, allowing degradation that later caused fatal organ failure in Cole. Under Model Penal Code section 2.03 the skipped test was an antecedent but for which Cole's death would not have occurred. The conduct therefore satisfied the causation element.
A law firm made contributions to a judicial candidate solely to obtain appointment as counsel in upcoming cases. The contributions would not have been made but for the desire to secure the government legal engagement. The conduct violated Model Rule 7.6.
The defendant traveled to the area of the intended crime and purchased supplies but left substantial steps undone. The overt acts remained so far from completion that the crime would not have occurred but for further uninterrupted action. No attempt liability attached under the common-law proximity test.
A new debtor acquired rights in collateral and perfected solely by a financing statement that would have been ineffective but for section 9-508. The interest was therefore subordinate to another security interest perfected by a different method under UCC section 9-326(a).
The test asks whether the result would have occurred without the defendant's conduct. If the harm would not have happened absent the act, the conduct is a but-for cause under the Model Penal Code and Durham rule formulations.
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The year-and-a-day rule can bar homicide liability even when but-for causation is clear. Death occurring after the period expires prevents the charge regardless of the strength of the causal link.
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No. The Code requires both that the conduct be an antecedent but for which the result would not have occurred and that any additional causal requirements imposed by the offense definition are satisfied.
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Relation back occurs when the new party knew or should have known that the action would have been brought against it but for a mistake concerning the proper party's identity, provided the other notice conditions are met.
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…Redlich, in advocating reliance on the Ninth and Tenth Amendments to invalidate the Connecticut law before us, frankly states: "But for one who feels that the marriage relationship should be beyond the reach of a state law forbidding the use of contraceptives, the birth control case poses a troublesome and challenging…