Records, reports, statements or data compilations, in any form, of public officials or agencies are not inadmissible under the hearsay rule if they set forth:

1. 1. The activities of the official or agency;
2. 2. Matters observed pursuant to duty imposed by law; or

3. 3. In civil cases and against the State in criminal cases, factual findings resulting from an investigation made pursuant to authority granted by law,

   unless the sources of information or the method or circumstances of the investigation indicate lack of trustworthiness.

(Added to NRS by 1971, 795)