The evidence needed to convict a person of a crime is also called the legal burden of proof. However, the weight of the burden of proof varies, depending on whether it is an administrative, civil or criminal court decision.
Preponderance of the Evidence
The "preponderance of the evidence" is the lowest burden of proof. A decision based on the preponderance of the evidence requires only evidence enough that a reasonable person could come to that conclusion; the evidence does not need to dispel any possibility of doubt. To meet this standard, the evidence need only convince a judge or jury that it is more likely than not that the defendant committed the offense. The preponderance of the evidence is sufficient in most administrative court decisions and many civil court decisions.
Clear and Convincing Evidence
"Clear and convincing evidence" requires that the judge or jury believe that, based on the evidence, the facts presented are highly probable or almost certain to be true. Like the preponderance of the evidence standard, clear and convincing evidence does not need to dispel all doubts. This is the most common standard of proof in civil trials.
Beyond a Reasonable Doubt
Evidence that is "beyond a reasonable doubt" must dispel any beliefs that the defendant did not do what he is accused of doing. This is the highest burden of proof. Criminal trials require the judge or jury to base convictions on evidence supporting guilt beyond a reasonable doubt.