The expert may testify in terms of opinion or inference and give reasons therefor without prior disclosure of the underlying facts or data, unless the court requires otherwise. The expert may in any event be required to disclose the underlying facts or data on cross-examination.
Minn. R. Evid. 705
Committee Comment-1989
Rule 705 streamlines the presentation of expert testimony leaving it to cross-examination to develop weaknesses in the expert's opinion. Obviously, if there is to be effective cross-examination the adverse party must have advance knowledge of the nature of the opinion and the basis for it. The procedural rules provide for much of this information by way of discovery. See Minn.R.Civ.P. 26 and Minn.R.Crim.P. 9.01 subd. 1(4) . In the case where the adverse party has not been provided with the necessary information to conduct an effective cross-examination, the Court should, if requested by the adverse party, exercise its discretion under the rule and require that a full foundation be established on direct examination.