The concept of res ipsa loquitur in personal injury cases in Illinois and across the nation means that the plaintiff can presume that the defendant was negligent without direct proof, using only circumstantial evidence. In these cases, the defendant instead bears the burden of showing that they did not act negligently.
Even so, the courts do not assume negligence on the part of a property owner after an accident. The plaintiff generally needs to show that negligence caused the injury. If the plaintiff does not have direct evidence, they can use circumstantial evidence in some situations. Circumstantial evidence simply means that a jury or rational person could infer negligence as the logical conclusion in a case based on general knowledge and experience.
The original case of res ipsa loquitur, which means ‘the thing speaks for itself,” is based on an incident when a barrel of flour fell on a plaintiff who was walking near a warehouse and was injured as a result. The courts determined that a rational person could assume that someone acted negligently by failing to close or block the window or store the barrel, resulting in the fall. Over time, the applications in each situation have developed as the courts have ruled on related cases. Each state has slightly different rules regarding a negligent property owner, but they generally follow a formula to determine if res ipsa exists. Courts must show that the individual in question was negligent, resulting in the incident, that the plaintiff or a third party did not cause the accident and that the defendant failed to exercise their duty to prevent the incident.
In some cases, a rational person and the jury can easily see that the defendant acted negligently when they apply the principles of res ipsa. A personal injury lawyer might argue that the factors for res ipsa exist in a case.