Cross examination is a process of witness interrogation, during which a lawyer questions a witness who has testified in favor of an opposing party. Cross examination is intended to either diminish the credibility of the witness, such that the weight of the unfavorable testimony is reduced, or to generate a favorable response from the witness.
In common law jurisdictions, cross examination is generally preceded by direct examination and can be followed by re-examination. In jury trials, cross examination is considered crucial, due to the impact it can have on the opinion of the jury and judge. Generally, the questions an attorney is allowed to ask during cross examination must be related to the subjects covered in the direct examination of the witness. However, an attorney is allowed to ask leading questions.
Lawyers use cross examination to try to get closer to the truth, to try to expand on information already provided, or to get new information.