Opinion ID: 1249059
Heading Depth: 4
Heading Rank: 2

Heading: Studies Experts Will Rely Upon

Text: The three apparently excludable documents the government identifies are studies that it expects various expert witnesses to rely upon at trial. The government explains that the studies: (1) show that exposure to lower levels of asbestos-contaminated vermiculite than were present in the Libby mines caused asbestos-related diseases; (2) examine the exposure to airborne asbestos fibers in Libby, Montana during various activities such as sweeping; and (3) differentiate between those forms of asbestos that are listed as hazardous and those that are not. We agree that these studies could be substantial proof of a material fact to the remaining charges. In sum, the government has supplemented its initial conclusory certification with enough specificity to demonstrate the materiality of the proffered witnesses and studies to support our jurisdiction under § 3731. We therefore turn to the question of whether the district court could properly exclude such evidence.