As an attorney with the Cook County Public Defender’s forensic science division, Richard E. Gutierrez spends many hours thinking about and challenging what’s accepted as evidence in the courtroom.Gutierrez helps his colleagues on complex forensic issues like latent fingerprint and firearms examinations as well as DNA analysis. As part of his job, Gutierrez regularly challenges prosecutors on whether certain scientific evidence they seek to introduce is admissible in court.Those challenges aren’t always …