People mix this up with the standard of proof, but they are not the same. The burden of proof is about who has to prove a claim or defense. The standard of proof is about how convincing that proof has to be. In a civil injury case, the injured person usually carries the burden of proof, and the usual standard is preponderance of the evidence - meaning more likely true than not.

That matters because filing a lawsuit is not enough. The side with the burden has to bring the facts: records, photos, bills, witness statements, expert opinions, and anything else that ties the injury to the event and shows the losses. If the evidence is thin, inconsistent, or shows long gaps in treatment, the claim can fall apart even if the accident clearly happened. A defendant may also have the burden to prove certain defenses, such as comparative negligence.

For a Massachusetts injury claim, timing and paperwork matter. Under Massachusetts General Laws Chapter 260, Section 2A, the deadline for most personal injury lawsuits is 3 years. Miss that window, and the case can be barred before anyone argues fault. On a crash scene, facts go stale fast - especially after a messy highway pileup or a long Route 3 backup where memories blur and vehicles disappear.