Every day, in courtrooms around the country, legal matters are being argued in front of judges and juries. In each case, the burden of proof and the standard of proof determine who has to prove what—and to what extent.
"Burden" and "standard" of proof are sometimes used interchangeably, but this article explains the important distinction between them.
In each case, one side has the "burden of proof." Having this burden means the party must prove its case to the "trier of fact"—the judge or jury, whoever is weighing the evidence. So, the party with the burden must produce evidence in support of their case. The standard of proof, on the other hand, refers to how convincing that evidence must be (more on that below).
Sometimes, the burden of proof can shift from one side to the other during a hearing or a trial depending on the kind of case.
The burden of proof is normally on the party trying to get the judge or jury to do something. Here's how it works in common types of cases:
Criminal cases. In a criminal trial, the state (represented by the prosecutor) is trying to do something—convict the defendant of a crime—so they have the burden of proving the defendant committed the crime. Because the state has the burden, the defendant doesn't have to produce any evidence at all; if the government hasn't met its burden, the defendant can just rely on that fact. Of course, in many cases, defendants do choose to present evidence to rebut the prosecution's case. And in many states, when the defendant raises affirmative defenses, they have the burden of proving those defenses (but by a lower standard than the state must meet).
Most civil cases. In civil trials involving most types of lawsuits, the plaintiff is trying to do something—get money for injuries or enforce a contract, for example. So, they have the burden to prove the claims in their lawsuit. Just as in criminal cases, if they don't meet their burden, they won't win, even if the defendant presents no evidence. Also similar to criminal cases, when defendants raise certain types of affirmative defenses, they usually have the burden of proving them.
The standard of proof refers to the extent to which the party with the burden of proof has to prove its case (or an element of its case). The higher the standard of proof, the more difficult it is for a party to meet their burden of proof.
In general, the higher the stakes are, the higher the standard of proof will be. So, a prosecutor in a criminal case has to meet a very high standard of proof, because a defendant's liberty is on the line. On the other hand, someone suing over a property dispute has a fairly low burden of proof because the stakes, while significant, aren't nearly as high.
The following are some examples of some common standards of proof:
Proof beyond a reasonable doubt. Because people can be incarcerated (and in rarer cases, put to death) if they're convicted of a crime, the prosecution faces the highest standard of proof required in the American legal system: proof beyond a reasonable doubt. Though states vary in how they define this standard, it's universally considered the toughest standard to meet.
Preponderance of the evidence. The most common civil standard of proof is "preponderance of the evidence" (meaning more likely than not). This standard is much lower than beyond a reasonable doubt because generally, disputes between people (or businesses) about money, contracts, property rights, and similar issues don't involve the state trying to take away someone's freedom. The preponderance of the evidence standard can also apply to certain aspects of a criminal trial. For example, when the defendant raises an affirmative defense, they often have to prove the defense only by a preponderance of the evidence (and some states have an even lower standard for defenses).
Clear and convincing. Some particular types of cases that are civil in nature but involve very important rights require "clear and convincing" evidence. This standard of proof is higher than a preponderance of the evidence but lower than proof beyond a reasonable doubt. Often, these cases involve the state trying to do something that affects someone's rights. For example, when a social services agency tries to take children from their parents, the agency usually must prove the parents are unfit by clear and convincing evidence.
Learn more in Standards of Proof at Trial.