1. 1. A witness may not testify to a matter unless:

   1. (a) Evidence is introduced sufficient to support a finding that the witness has personal knowledge of the matter; or
   2. (b) The witness states his or her opinion or inference as an expert.
2. 2. Evidence to prove personal knowledge may, but need not, consist of the testimony of the witness.

(Added to NRS by 1971, 788)