Unless the court orders otherwise, an expert may state an opinion - and give the reasons for it - without first testifying to the underlying facts or data. But the expert may be required to disclose those facts or data on cross-examination.
N.H. R. Evid. 705
2016 NHRE Update Committee Note
The amendment made by supreme court order dated April 20, 2017, effective July 1, 2017, made stylistic and substantive changes to the rule.
For additional guidance regarding changes to the rule see the notes following Federal Rules of Evidence 705 (Notes of Advisory Committee on 1993 amendment).