People v. Zackowitz, 254 N.Y. 192, 172 N.E. 466 (N.Y. 1930)
People v. Zackowitz is a landmark New York Court of Appeals decision, authored by Judge Benjamin Cardozo, that crystallizes the modern prohibition on propensity reasoning in criminal trials.
May the prosecution, in its case-in-chief, introduce evidence that the defendant possessed other weapons unconnected to the charged homicide to show his violent disposition or a general propensity for using deadly force, and thereby prove intent, malice, or premeditation?
The prosecution may not prove a defendant's guilt by showing his bad character or propensity to commit crime. Evidence of other acts or possessions (such as additional weapons) is inadmissible when offered solely to show a defendant's general disposition or likelihood to have acted in conformity therewith. Such evidence becomes admissible only if it has a legitimate, non-propensity purpose—e.g., to prove motive, intent, identity, absence of mistake or accident, a common scheme or plan, or another material fact—and there is a specific, articulable nexus connecting the other act or item to the charged offense. Even then, the trial court must exclude the evidence if the risk of unfair prejudice substantially outweighs its probative value (as reflected in New York's Molineux doctrine and consistent with modern balancing principles).
No. The evidence of other weapons found in the defendant's home, unconnected to the homicide, was inadmissible because it served only to portray the defendant as a dangerous person with a propensity for violence. Admitting it was reversible error, requiring a new trial.
People v. Zackowitz is a cornerstone case on the prohibition of propensity evidence in criminal trials. It frames the analytical steps students must master: identify the proponent's purpose, test for a genuine non-propensity chain of relevance, demand a concrete nexus to material issues in dispute, and then weigh prejudice against probative value. The case also situates New York's Molineux exceptions within a broader policy that justice focuses on what the defendant did on the occasion charged, not who he is in general. Its reasoning presages the structure of modern Rule 404 and Rule 403 analyses and is frequently cited to exclude sensational but marginally probative evidence offered to smear a defendant's character.