Testimony given by someone under oath during a trial — or other court-sanctioned proceeding, such as a hearing or deposition — can be examined and challenged by either side of a legal party. This process is known as witness impeachment. The word impeach means to question someone’s integrity or ability to perform a job or task. 

If one side to a legal case wants to impeach a witness this basically means they do not want the witness’ testimony to sway the decision maker or have any influence as to the outcome of the case. Testimony are the answers and information given during court proceedings and witness testimony is evidence. 

During legal proceedings, the rules of evidence must be followed by the attorneys, or pro se parties, involved in a case. The purpose of the rules of evidence is to provide structure to and control the information that a jury or judge is allowed to hear and see. The rules of evidence can vary from state-to-state. There are also Federal Rules of Evidence that must be adhered to when involved in a federal court matter.

What are Some Examples of Impeaching a Witness?

There are several different methods to impeaching a witness.

This includes introducing evidence that shows:

  • Bias: If the witness is biased and cannot give a fair account of events or provide impartial information, they may be impeachable. For example, a close relative such as a parent may not be able to put aside their personal views about their loved one when testifying. If a witness is unable to provide fair, unbiased and accurate information, their testimony should not be allowed as witness evidence during court proceedings.
  • Prior Inconsistent Statements: When a witness has given prior statements that are inconsistent with current statements, the witness could be considered an impeachable witness. For instance, if the witness made a statement to the police and later the “story” changed in court — that witness’ credibility can come under question and may not be included as testimony.
  • Criminal Past: If a witness has a prior criminal record, their credibility may come under question. Typically, crimes that involve deceit or untruthfulness — for example, perjury, giving a false statement, criminal fraud and embezzlement may warrant impeachment of a witness. Felony crimes also may give rise to witness impeachment.
  • Incapacity: Should a witness have a mental disability that may affect the accuracy of information provided to the court, they may be an impeachable witness. An example may include someone that has a memory disorder and cannot recall prior events and information.
  • Reputation for Lying: In some jurisdictions, if there is evidence to substantiate a claim that a witness has a reputation for dishonesty, their testimony may be impeached by a judge.

There are several other methods to impeachment. The methods used to impeach a witness and introduced in a courtroom hearing, trial or during a deposition will vary from case-to-case. While the goal of impeaching a witness is to remove and discredit the witness’ testimony, how a witness impeachment proceeds depends on the situation and the circumstances of the individual case.

What are the Consequences of Impeaching a Witness?

Ultimately, a judge will decide whether or not a witness is impeachable. They will weigh in on the information presented by the party wishing to impeach the witness as well as the other party or parties involved. The judge will decide if the witness testimony is to be included or excluded as part of the case.

The initial threshold to deem a witness credible is low. A witness is presumed to be trustworthy. The basic requirements to be a credible witness include that the person has knowledge and memory of the events and takes an oath — makes a promise — to tell the truth. 

If the credibility of a witness has been attacked, the opposing party may introduce information to rebut the attack or share information about the witness that shows they have been rehabilitated. 

If a judge decides to impeach a witness, then the testimony made by that witness is no longer considered credible or admissible in court proceedings. 

Should I Contact an Attorney for Questions About Witness Impeachment?

If you are involved in a court case and believe that a witness’ testimony may not accurately reflect the facts surrounding the case, it is imperative to contact an experienced and knowledgeable criminal law attorney that can assist you with the best way to proceed. 

The elimination or inclusion of witness testimony during a court hearing, deposition or trial may be the deciding factor for the judge or jury regarding the matter.

While witness impeachment is commonly handled across the country, each state has its own rules of evidence. It is important to work with an attorney well-informed with the local rules and procedures. This will ensure that all possible scenarios are covered for your particular circumstances.