A witness is a person who has knowledge related to this case. You will have to decide whether you believe each witness and how important each witness’s testimony is to the case. You may believe all, part, or none of a witness’s testimony. In deciding whether to believe a witness’s testimony, you may consider, among other factors, the following: (a) How well did the witness see, hear, or otherwise sense what the witness described in court? (b) How well did the witness remember and describe what
happened? (c) How did the witness look, act, and speak while testifying? (d) Did the witness have any reason to say something that was not true? For example, did the witness show any bias or prejudice or have a personal relationship with any of the parties involved in the case or have a personal stake in how this case is decided? (e) What was the witness’s attitude toward this case or about giving testimony? Sometimes a witness may say something that is not consistent with
something else the witness said. Sometimes different witnesses will give different versions of what happened. People often forget things or make mistakes in what they remember. Also, two people may see the same event but remember it differently. You may consider these differences, but do not decide that testimony is untrue just because it differs from other testimony. However, if you decide that a witness did not tell the truth about something important, you may choose not to believe anything that witness said. On the other hand, if you think the witness did not tell the truth about some things but told the truth about others, you may accept the part you think is true and ignore the rest. Do not make any decision simply because there were more witnesses on one side than on the other. If you believe it is true, the testimony of a single witness is enough to prove a fact.”
[CACI Jury Instructions [citations omitted]]
