Regardless of the area of law, if you plan to present an expert witness for testimony, you need to think about expert witness trial testimony before and during expert witness selection, as well as early on in your working relationship. Here are four tips for you to consider in this regard.From the time you first consider hiring an expert witness, ask yourself what critical elements of the cause of action will be established through the expert witness testimony. Is it causation between an event and an injury? Is it assignment of liability between co-defendants? Start your selection process by thinking about the trial and working backwards. In your imagination, create the perfect expert testimony, then take out a piece of paper and write down the education, training, and work expertise would be required to be competent to provide that dream testimony.Then, use your vision of the ultimate trial expert testimony and your checklist of desired credentials to vet out the candidates for your expert witness. It is a job interview. You are looking for the candidate who understands your theory of the case, who is genuinely interested, and who has the credentials to add to your investigation, development, and presentation. So when you receive that 20-page resume, take the time to read through it and also some of the publications listed. Your opposing counsel will do so as soon as you transmit it, so your best approach is to do so during the selection process.Secure the terms of employment of your expert witness in writing. As with any contract, create a clear document that will stand the test of a multi-year relationship. Cases that require expert witnesses generally signal complex litigation. While only a small fraction of a lawyer’s time is spent with the expert witness, it is crucial that when the expert witness is needed, each person understands what to expect. For example, will the expert witness review court documents, such as motions, to assist with supporting, responsive affidavits? Try to think about the functionality of the expert witness from the time you sign the retainer agreement in order to avoid costly delays on the way to trial.Finally, listen to the questions asked by your expert witness. Many expert witnesses will verbally reel off a list of documents they would like to review, as soon as they are hired. The source materials an expert defines as routine can haunt you at trial if not obtained and provided to the expert in the course of the litigation. The last thing you will want at trial during a cross-examination of your expert witness is that s/he asked for something that you didn’t provide, particularly if it is part of what you obtained and reviewed during your own preparation.