What standard is used in criminal trials to prove a defendant is guilty?
The prosecutor must convince the judge or jury hearing the case that the defendant is guilty “beyond a reasonable doubt.” This standard is very hard to meet. (By contrast, in noncriminal cases, such as an accident or breach of contract, a plaintiff has to prove her case only by a preponderance of the evidence — just over 50%.) As a practical matter, the high burden of proof in criminal cases means that judges and jurors are supposed to resolve all doubts about the meaning of the evidence in favor of the defendant. With such a high standard imposed on the prosecutor, a defendant’s most common defense is to argue that there is reasonable doubt — that is, that the prosecutor hasn’t done a sufficient job of proving that the defendant is guilty.
