(2) the quality of the witness's understanding and memory;
(3) the witness's manner while testifying;
(4) whether the witness has an interest in the outcome of the case or any motive, bias or prejudice;
(5) whether the witness is contradicted by anything the witness said or wrote before trial or by other evidence;
(6) how reasonable the witness's testimony is when considered in the light of other evidence that you believe; and
(7) any other factors that bear on believability.
COMMENT
This instruction is derived from First Circuit (Criminal) 1.06 and former Ninth Circuit 1.8. Cf. Ninth Circuit 1.11. For variations, see Sixth Circuit (Criminal) 1.07; Seventh Circuit (Criminal) 1.03.This instruction can be given both at the beginning of the case and at the close of the evidence. For an example of an instruction given at the end of the case, see Eighth Circuit 3.03.
The bracketed material at the end of the instruction may be given usefully at the end of a case in which witnesses on one side outnumber the other. See Instruction 3.2 (Number of Witnesses).
