§ 1643 - Expert witness
§ 1643. Expert witness
An expert witness may be asked to state his opinion based on the witness' personal observation, or on evidence introduced at the trial and seen or heard by the witness, or on his technical knowledge of the subject, without first specifying hypothetically in the question the data on which this opinion is based. On direct or cross-examination, such expert witness may be required to specify the data on which his opinion is based.