In legal matters, the burden of proof refers to the duty of a party making allegations to substantiate them with evidence that is admissible in court. In a civil lawsuit, the plaintiff carries this responsibility. When a person has been accused of a crime in the United States, Canada, the United Kingdom and several other countries around the world, the burden rests with the prosecution, which must prove the charges before a conviction can be obtained.
Standards of proof can be different depending on the type of legal dispute in question. In a criminal trial, the prosecution is required to prove its case beyond a reasonable doubt. The individual who has been accused of a crime is presumed to be innocent until proven guilty.
When a judge gives instructions to a jury before they retire to deliberate, he or she will explain the burden of proof and how it applies to the proceeding. The prosecution is not required to convince the jury of the accused person's guilt beyond all doubt. Instead, the juror must be able to say to him or herself with moral certainty that the individual is guilty of having committed the crime. If the jurors are not able to do so, the prosecution has not met the burden of proof and the jury must find the person not guilty.
In a civil trial, the burden of proof rests with the plaintiff. He or she needs to be able to support allegations of loss or injury to collect damages from the defendant. The standard usually applied in these situations is one of preponderance of the evidence. This term may also be called the balance of probabilities.
The preponderance of evidence means that a judge or jury must be satisfied that the defendant's actions or lack thereof caused the plaintiff to be injured or wronged in some fashion. Technically speaking, if there is only a 50 percent chance that this is true, the defendant may be held legally responsible. Being held liable in a civil action means that the defendant will be ordered to pay money to compensate the plaintiff for his or her loss.
Another way the burden of proof comes into play in a civil trial is the principle of clear and convincing evidence. This is a higher standard than the preponderance of evidence. In this situation, the plaintiff's attorney must use a higher standard to convince a judge that the allegations forming the basis for the action are true.