If a witness of a criminal trial recants on the stand, how would treating him/her hostile favor the attorney who called him/her?

Question

It's a valid method with witnesses unwilling to tell the truth, but I don't know how it would be useful. You'd at least need proof (s)he lied. And the jury naturally will trust more the witnesses called by the other side.

Answer 1

It's useful because it allows the examining party to ask leading questions, which can be used to introduce information that the witness does not want to volunteer. For example, on direct examination, it's not usually permissible to ask "did you next see the defendant strike the victim?"; instead, the question must be "what did you see next?" A hostile witness may be expected to answer evasively by describing other things that were observable incident to the acts for which the defendant was charged, such as "I saw a taxi picking up a passenger across the street." Allowing leading questions gives the examiner more control over the narrative flow of the testimony and, therefore, over the facts that are entered into the record.

It also allows the examiner to impeach the witness's testimony, calling into question its credibility.