CALIFORNIA EVIDENCE: CIVIL AND CRIMINAL
...Witness Credibility Evidence
......Opinion Evid. Admiss. re Credibility
3 Cards On This Topic:

O's testimony about a witness' information being "critical" did not constitute inadmissible opinion about his credibility as a witness.

Opinion testimony re honesty and veracity of DA's witness admissible to attack credibility.

Opinion re character of witness must be based upon personal knowledge.