Accuracy of Eyewitness Accounts in the Investigative Stage: Behavioral, Psychological and Environmental Issues that May Impact Credibility of Witness Accounts. This assignment is not about courtroom testimony or about how the law enforcement officer goes about interrogating the eyewitness. This is about the conditions that impact the credibility of the information the witness is providing based on factors that impact that witness. Keep the focus on the witness, not others. Required textbook for any additional information, Introduction to Forensic Psychology research and application (6th edition). Arthur Curt R. Bartol, Anne M. Bartol.