Burden of proof refers to the amount of evidence or proof required to adequately prove disputed facts in a court of law, and which party has the obligation to prove the disputed facts in order to prevail in court. In criminal prosecutions (cases) the government or prosecution has the burden to prove the accused defendant’s guilt beyond a reasonable doubt. This has been the standard for criminal prosecutions in the United States since at least 1880 when it was first mentioned by the U.S. Supreme Court. The determination of whether there is reasonable doubt as to an accused defendant’s guilt may be characterized by the question of whether there is an alternative explanation of the facts that seems plausible to the jurors.

In Kansas, as in all states across the United States, the burden of proof in criminal prosecutions lies with the government or prosecution. This means that it is the responsibility of the prosecution to prove the defendant's guilt 'beyond a reasonable doubt.' This standard is the highest in the American legal system and requires the prosecution to present evidence that leaves no reasonable doubt in the mind of a reasonable person about the defendant's guilt. If the jurors find that there is a plausible alternative explanation of the facts that could suggest the defendant's innocence, they are obliged to acquit. This standard has been a cornerstone of the U.S. criminal justice system since it was articulated by the U.S. Supreme Court in 1880 and is designed to protect the accused by ensuring that no one is convicted based on insufficient or ambiguous evidence.