Written testimonies must never be underestimated either. Listeners want to SEE the person who is testifying if at all possible. It adds believability to what the person is saying. When using the medium of video to record someone's testimony, there are TWO critically important factors that need to be taken into consideration. It is easy to obtain both with a little bit of understanding.
Good sound is critical because people simply refuse to listen to bad sound on video.
People are used to good sound on videos, so to give them noise or weak sound is all that is needed to get them to NOT listen to your testimony. When using a standard camcorder, it is best to have an extension microphone that plugs into the side of the camcorder. This eliminates camcorder noise, as well as other background noise. Of course, a wireless microphone works well, but a decent quality one is not cheap to buy. Batteries get weak, whereas a handheld mike doesn't need batteries.