Impeachment may refer to different legal concepts. One meaning in the law refers to discrediting a witness by showing that he or she is not telling the truth or does not have a reliable basis for their testimony. Rules of evidence govern what type of questioning may be used to impeach a witness. Generally, unrelated evidence that the person is a" bad person" and therefore untrustworthy, is not allowed.
Impeachment also refers to the trial of a public official for charges of illegal acts committed in the performance of public duty. It is the constitutional process, not the conviction or removal from office, whereby the House of Representatives may "impeach" (accuse of misconduct) high officers of the federal government for trial in the Senate.
