What is res ipsa loquitur?

This Latin term literally means the thing speaks for itself. In legal parlance, it refers to a doctrine that helps a plaintiff show that a defendant was negligent when the injury-causing instrument was under the control of the defendant and it is probable that the negligence resulted from the defendant. As a Connecticut court wrote, res ipsa loquitur is a method to prove negligence as opposed to being a separate tort in and of itself.

Res ipsa loquitur applies when the rational explanation for the plaintiff’s injuries was because of the defendant’s negligence. The doctrine is an exception to the general rule that negligence cannot be presumed from the mere occurrence of an accident and injury. A Nebraska appeals court applied the doctrine when a property owner sued after a high voltage line maintained by a local power district fell onto their property and started a fire. The court noted that powerlines do not normally fall without fault on behalf of the company that maintains them and that res ipsa loquitur is applied in the absence of a substantial, significant, or probable explanation.