Legal Definitions - actual cause

Actual Cause refers to the direct link between a specific action or omission and a resulting harm or injury. It is a fundamental concept in both civil and criminal law, serving as the initial step in determining whether someone can be held legally responsible for an outcome.

The most common method for establishing actual cause is the "but-for" test. This test asks: "But for the defendant's action (or inaction), would the harm or injury have occurred?" If the answer is no – meaning the harm would not have happened without that specific action – then actual cause is established. It's important to note that while actual cause is necessary, it is often not sufficient on its own to establish legal liability; another element called proximate cause typically also needs to be proven.

Here are some examples illustrating actual cause:

• Example 1 (Civil Negligence): A delivery driver, rushing to meet a deadline, fails to secure a stack of boxes in their truck. When the driver makes a sharp turn, the boxes slide out and hit a pedestrian walking on the sidewalk, causing the pedestrian to suffer a concussion.

  Explanation: Applying the "but-for" test, we ask: "But for the driver failing to secure the boxes, would the pedestrian have suffered a concussion?" The answer is no. If the boxes had been properly secured, they would not have fallen out and hit the pedestrian. Therefore, the driver's failure to secure the boxes is the actual cause of the pedestrian's injury.

• Example 2 (Criminal Assault): During a heated argument, one person intentionally shoves another, causing them to lose their balance, fall down a short flight of stairs, and break their wrist.

  Explanation: Using the "but-for" test, we consider: "But for the first person shoving the second person, would the second person have fallen and broken their wrist?" The answer is no. The shove directly initiated the sequence of events leading to the fall and injury. Thus, the shove is the actual cause of the broken wrist.

• Example 3 (Civil Product Liability): A manufacturer produces a batch of children's toys with a design flaw that allows small parts to easily detach. A child swallows one of these detached parts and requires emergency medical attention.

  Explanation: Applying the "but-for" test, we ask: "But for the manufacturer's design flaw allowing the small part to detach, would the child have swallowed it and required medical attention?" The answer is no. If the part had been securely attached as intended, the incident would not have occurred. Therefore, the manufacturer's design flaw is the actual cause of the child's injury.