Section 802 Of Article 1. Expert And Other Opinion Testimony Generally From California Evidence Code >> Division 7. >> Chapter 1. >> Article 1.
802
. A witness testifying in the form of an opinion may state on
direct examination the reasons for his opinion and the matter
(including, in the case of an expert, his special knowledge, skill,
experience, training, and education) upon which it is based, unless
he is precluded by law from using such reasons or matter as a basis
for his opinion. The court in its discretion may require that a
witness before testifying in the form of an opinion be first examined
concerning the matter upon which his opinion is based.