What Is Burden of Proof?
The obligation a party has to prove their case to a certain level of certainty. In criminal cases, the prosecution bears this burden and must prove guilt beyond a reasonable doubt. In civil cases, the burden is usually on the plaintiff to prove their case by a preponderance of the evidence.
Quick Answer
The obligation a party has to prove their case to a certain level of certainty. In criminal cases, the prosecution bears this burden and must prove guilt beyond a reasonable doubt. In civil cases, the burden is usually on the plaintiff to prove their case by a preponderance of the evidence.
Full Explanation
The burden of proof has two components: the burden of production (the obligation to present sufficient evidence that a reasonable jury could rule in your favor) and the burden of persuasion (the obligation to convince the fact-finder to a specific level of certainty).
There are three main standards. 'Preponderance of the evidence' means more likely than not — the fact is probably true. This is the standard in most civil cases. 'Clear and convincing evidence' is an intermediate standard requiring highly probable certainty — it is used in cases like fraud, some family law matters, and certain constitutional contexts. 'Beyond a reasonable doubt' is the highest standard and applies only in criminal cases.
In criminal cases, the prosecution always bears the burden of proof. The defendant is presumed innocent until proven guilty, so the state must affirmatively prove each element of the crime. The defendant generally does not have to prove anything — though they may bear the burden on affirmative defenses like insanity or self-defense in some jurisdictions.
In civil cases, the burden allocation depends on the type of claim. Plaintiffs generally bear the burden on their claims; defendants bear the burden on affirmative defenses.
Real-World Example
O.J. Simpson illustrates the different standards dramatically. He was acquitted in his 1995 criminal trial, where the prosecution had to prove guilt beyond a reasonable doubt. But he was found liable in his 1997 civil trial, where the plaintiffs only needed to prove their case by a preponderance of the evidence — more likely than not.
The same evidence, the same facts, but two different outcomes — because the legal standard required for each type of case is different.
Why It Matters for Law Students
The burden of proof is one of the most fundamental concepts in litigation. It determines who must prove what, how convincingly, and what happens in a tie. Understanding the different standards — and when each applies — is essential for every law student and appears throughout the bar exam.