CALIFORNIA EVIDENCE: CIVIL AND CRIMINAL
...Method of Exam: Cross-Exam
......Bias or Improper Motive
.........Hostility to Party
3 Cards On This Topic:

Party may prove that witness hostile to person against whom he testifies, but may not prove cause of hostility.

Evidence that D's girlfriend asked officer for help and did not get it was clearly relevant to her credibility because it could have provided a reason for her hostility to the prosecution.

May not impeach witness by showing hostility towards another witness, only against party.