For those of us doing a lot of CP cases – LimeWire, one of several peer-to-peer file sharing programs, is increasingly found to be the method by which CP is received or transmitted. Typically the prosecution calls a forensic computer examiner as an expert witness (although I notice the Navy is trying to short-circuit this by calling the duty NCIS agent to testify about computers). Anyway, FEB notes the difficulty courts are having in deciding whether testimony about computers and/or software falls within [Mil. ]R. Evid. 701 (lay) or 702 (expert).
[T]he line between lay and expert testimony is very hard to discern. A closer question would have been raised in the case if an objection had been made at trial and review was under the less deferential abuse of discretion standard. The issue of lay versus expert testimony arises in other contexts, including on computer forensic testimony, as noted in these prior posts: Drawing The Line On Computer Forensic Expert And Lay Testimony (Part I); Drawing The Line On Computer Forensic Expert And Lay Testimony (Part II).