“Do you swear to tell the truth … and nothing but the truth?”
—Question asked before testifying in court
When in court, investigators and fraud fighters should present a professional appearance with good bearing and be mindful of their own personal conduct. Remember that some of the same people you might speak to in the courtroom might see you before or after you enter the courtroom. So stay in “professional mode” at all times, even in the building's parking lot, hallways, or other nearby areas.
Be prepared to testify by reviewing the case facts before showing up. If the facts are fresh in your memory you should do fine when testifying. It can't hurt to mentally rehearse before going inside the building.
TIP: In some of the training classes I've attended, the instructors filmed the students' participation in certain exercises, including testifying in mock courtroom trials and while conducting mock interviews and interrogations. It's amazing how much you can learn to improve by watching yourself (and others) on tape. As a PI, I usually critique the audio-recorded interviews I conduct when playing them. Professional athletes, coaches, and trainers also use videotape to analyze athletes' movements to ensure they are using proper techniques. Sometimes slight adjustments make a huge difference in performance. Be your own best critic.
If you've never been in a courtroom, do yourself a favor and go into one—preferably while some form of hearing is going ...