Why would a judge let the jury assume missing evidence would have hurt the side that lost or destroyed it? That is an adverse inference: a rule a court may use when someone had control of relevant evidence, had a duty to preserve it, and then failed to keep it. The judge can allow jurors to infer that the missing photo, log, video, vehicle data, or document would have been unfavorable to that party. It often comes up after spoliation of evidence, whether the loss was deliberate or so careless that it undermines a fair case.

In practical terms, adverse inference can change the balance of proof. If a trucking company loses driver logs after a crash, or a business fails to keep surveillance footage after a fall, the missing evidence may no longer be neutral. The court may treat its absence as a sign that the evidence would have supported the injured person's version of events. That can affect liability, causation, and settlement value.

For an injury claim, this matters most early. Sending a preservation letter quickly can help show the other side was on notice to keep evidence. In North Dakota, courts can address lost evidence through sanctions under North Dakota Rule of Civil Procedure 37 and related spoliation principles. On roads used by heavy Bakken truck traffic, missing electronic records or maintenance files can become a major issue fast.