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"—judge or jury, whoever is weighing the evidence. The burden of proof can shift from one side to the other during a hearing or a trial depending on the kind of case.
For example, in a criminal trial, the prosecution has the burden of proving the defendant committed a crime. In many states, the defendant has the burden of proving certain defenses to that crime. But, particularly in criminal cases, opposing sides can be held to different standards of proof.
PRESUMPTION OF INNOCENCE
The "presumption of innocence" refers to our critical constitutional right to have the government prove us guilty of crime rather than prove ourselves innocent. In other words, the government has the burden of proving a criminal case, and the accused is always innocent until proven guilty.
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). In general, the higher the stakes, the higher the standard of proof. A higher standard of proof means that, to find for the side with the burden of proof, the trier of fact has to be more certain that that side has proved its case.
For much more about the standards of proof, see Standards of Proof at Trial.