A failure by investigators, such as CID or NCIS, to investigate credible alternate suspects can be a significant due process violation that a defense attorney can use to challenge a sexual assault prosecution. While investigators are not required to chase down every fanciful lead, if the defense provides them with credible information pointing to a plausible alternate suspect, the investigators have a duty to conduct a reasonable inquiry. Their goal is supposed to be to find the truth, not just to build a case against the initial suspect.
If the investigators fail to do this, a military defense attorney can argue that the investigation was biased, incomplete, and fundamentally unfair. During a court-martial, the attorney would cross-examine the lead investigator about their failure to pursue the other leads. They would ask the agent why they chose not to interview the alternate suspect or to follow up on the evidence provided by the defense. This can make the entire investigation appear incompetent or biased in the eyes of the court-martial panel.
The attorney will also present the evidence about the alternate suspect directly to the panel as part of the defense case. They will argue that the government has not met its burden of proving their client’s guilt beyond a reasonable doubt because there is another person who could have committed the crime. The failure of the investigators to properly look into this other person creates a powerful reasonable doubt. This strategy shifts the focus from the client and places the quality and integrity of the government’s investigation on trial.