United States v. Scop, 846 F.2d 135 (2d Cir. 1988)

'Rule 704 was not intended to allow experts to offer opinions embodying legal conclusions' (at 139); the witness's opinions 'drew directly upon the language of the statute and accompanying regulations concerning "manipulation" and "fraud"... In essence, his opinions were legal conclusions that were highly prejudicial and went well beyond his province' and were 'calculated to "invade the province of the court to determine the applicable law and to instruct the jury as to that law"' (at 140).