A defense expert witness is a type of expert who has specialized training skills or education in a certain topic or subject. He may be called upon during a court hearing to testify for the defendant. His expertise should be well established by the court before he is considered as an expert witness by his educational background and area of expertise.
A defense expert witness is an option for the court or the disputing parties to be enlightened or educated by the witness in a certain subject of the case. The qualifications of the expert witness should be well specified and proven in front of the judge and the jury because he would be the one who will study the evidence presented in the court. The jury will be listening not to his personal opinions regarding the case but more on the facts he would be able to state based on his reliable methods. The defense expert witness will most likely be countered by the prosecution who is also allowed to hire his own expert witness. That is why the defense witness should show confidence in all of his answers and must be straight forward in terms that the jury would be able to understand. The witness will be hired in favor of the defendant by the defense counsel in hopes that the witness will provide facts and evidences that may sway the jury and judge to the defense side, although he may share evidence that he has discovered pro or against the defendant.