Cross-examination is generally limited to questioning only on matters that were raised during direct examination. Leading questions may be asked during cross-examination, since the purpose of cross-examination is to test the credibility of statements made during direct examination.
When a lawyer calls an adverse or hostile witness (a witness whose relationship to the lawyer’s client is such that his testimony is likely to be prejudicial) on direct examination, the lawyer can ask leading questions as on cross-examination.
On cross-examination, the attorney might try to question the witness’s ability to identify or recollect, or try to impeach the witness or the evidence. Impeach in this sense means to question or reduce the credibility of the witness or evidence. The attorney might do this by trying to show prejudice or bias in the witness, such as his or her relationship or friendship with one of the parties, or his or her interest in the outcome of the case. Witnesses may be asked if they have been convicted of a felony or a crime involving moral turpitude (dishonesty), since this is relevant to their credibility.