Expert Witness Precluded from Referring to Ballistics Identification as a Science or Implying Any Degree of Certainty as to Conclusions

In United States v. Dore and Barrett, Docket No. 12 Cr. 45 (RJS) (SDNY), the government sought to have an expert witness testify  that multiple shell casings recovered from the scene of a robbery and a single shell casing recovered at the scene of a subsequent robbery/homicide had all been fired from the same weapon. A hearing pursuant to Daubert v. Merrell Dow Pharamaceuticals, Inc., 509 U.S. 579 (1993) was held based on the defense’s argument that the expected testimony did not meet the threshold of admissibility under Rule 702 of the Federal Rules of Evidence.

In an order dated March 11, 2013, the district court found that the government had not carried its burden to show that ballistics identification is a “science,” and also failed to establish that the expert had a reliable basis for testifying that the ballistics match could be stated with any degree of certainty (“when pressed on the issue, [the witness] admitted that the determination of whether or not a match existed is a subjective determination that the quality and quantity of similar markings on two shell casings is sufficient. He was unable to articulate a definition or standard for measuring ‘sufficiency,’ but, in essence, testified that he ‘knows it when he sees it’ based on his experience and training.”).

Based on those findings, the district court prohibited the witness from referring to his methods as “science or scientific,” or “using language that implies a specific degree of certainty as to his conclusion that there is a match between the shell casings.” Instead, the witness would be limited to explaining how markings are created on shell casings, the methods of comparison he used, and his opinion that the casings all came from the same gun.