Under California law there is a presumption that if you are struck in the rear, that it is the fault of the person who struck you. It is what is called in the law a “rebuttable presumption,” and what’s meant by a “rebuttable presumption” is it’s not 100 percent concrete that it’s always the other person’s fault, but it is normally considered the other person’s fault. So, if you jam on your brakes for no reason at all and someone rear-ends you, it may not be their fault.

On the other hand, typically, if you jam on your brakes for a good reason such as a car wreck up ahead, or the person in front of you jams on their brakes and you get rear-ended, it is the other person’s fault because it is every driver’s responsibility to leave a safe distance ahead.