From Siggelko v. Kohl’s Dep’t Stores, Inc., 2009 U.S. Dist. LEXIS 21223 (E.D.N.Y. Mar. 16, 2009):

A party's intentional destruction of evidence relevant to proof of an issue at trial can support an inference that the evidence would have been unfavorable to the party responsible for its destruction. See Kronisch v. United States, 150 F.3d 112, 126-128 (2d Cir. 1998) (citing Nation-Wide Check Corp. v. Forest Hills Distributors, 692 F.2d 214, 217-18 (1st Cir. 1982); 2 John Henry Wigmore, Evidence in Trials at Common Law § 291 (James H. Chadbourn rev. 1979). This adverse inference rule is based on evidentiary, prophylactic, punitive, and remedial rationales. Id. at 126. The court in Kronisch explained those rationales at length:

The evidentiary rationale derives from the common sense notion that a party's destruction of evidence which it has reason to believe may be used against it in litigation suggests that the evidence was harmful to the party responsible for its destruction. The prophylactic and punitive rationales are based on the equally commonsensical proposition that the drawing of an adverse inference against parties who destroy evidence will deter such destruction, and will properly "plac[e] the risk of an erroneous judgment on the party that wrongfully created the risk." Nation-Wide Check, 692 F.2d at 218. Finally, courts have recognized a remedial rationale for the adverse inference — namely, that an adverse inference should serve the function, insofar as possible, of restoring the prejudiced party to the same position he would have been in absent the wrongful destruction of evidence by the opposing party.

Id. (additional citations omitted)

In order for an adverse inference to arise from the destruction of evidence, the party having control over the evidence must have had an obligation to preserve it at the time it was destroyed. Fujitsu Ltd. v. Federal Exp. Corp., 247 F.3d 423, 436 (2d Cir. 2001) (citing Kronisch, 150 F.3d at 126). This obligation only arises when the party has notice that the evidence is relevant to litigation, either because suit has already been filed or because a party should have known that the evidence may be relevant to future litigation. Kronisch, 150 F.3d at 126. Once a court has concluded that a party has this obligation, it must then consider whether the evidence was intentionally destroyed, and the likely contents of that evidence. Fujitsu, 247 F.3d at 436 (citing Kronisch, 150 F.3d at 127). In the context of deciding a motion for summary judgment, a court must construe all facts in favor of the non-moving party; thus, a court must assume a party has intentionally destroyed evidence that it had an obligation to preserve. Kronisch, 150 F.3d at 127. But this does not end the court's inquiry. For a court to impose sanctions for destruction of this evidence, Plaintiff must still make some showing that the destroyed evidence would have been relevant to the contested issues. Id. (citing, inter alia, Stanojev v. Ebasco Servs., Inc., 643 F.2d 914, 923-24 (2d Cir. 1981) (refusing to draw inference, based on non-production of personnel records, that the records would have substantiated plaintiff's age discrimination claim, where the non-production bore "no logical relationship to a finding of age discrimination" because "the documents [were] from a time period prior to [plaintiff]'s assumption of the position from which he was discharged").

The destruction of evidence can alone raise the inference that the contents were unfavorable to the possessor. Id. (citing 2 Wigmore, Evidence in Trials at Common Law § 291, at 228). Thus, where the innocent party has produced some meaningful evidence in support of his claim, the intentional destruction of relevant evidence by the opposing party may push a claim that might not otherwise survive summary judgment over the line. Id. at 128. But the destruction of evidence, standing alone, is not enough to allow a party who has produced no evidence — or utterly inadequate evidence —- in support of a given claim to survive summary judgment on that claim. Id. (citing Nation-Wide Check, 692 F.2d at 218-19).

Finally, the determination of an appropriate sanction for spoliation, if any, is confined to the sound discretion of the trial judge. See West v. Goodyear Tire & Rubber Co., 167 F.3d 776, 779 (2d Cir. 1999), and is assessed on a case-by-case basis.