Usually, the standard of proof required in tort cases is 'preponderance of the evidence'. However, some cases need a higher standard like 'clear and convincing evidence'; and rarely, the highest standard - 'beyond a reasonable doubt'.
When it comes to law, burden of proof is a concept that is derived from the Latin term 'onus probandi'. The term denotes the duty placed on a party to a case, to prove or disprove a disputed fact(s). The party who bears the burden of proof has to prove the charge, allegation, claim, or defense, during the trial.
For example, a person who files a product liability suit has to prove that the product he bought was indeed defective or dangerous. The legal definition of burden of proof is: "The necessity or duty of affirmatively proving a fact or facts in dispute on an issue raised between the parties in a case."
Usually, it lies with the prosecutor in a criminal case, and the plaintiff in a civil case. If the prosecutor/plaintiff succeeds in proving the charges/allegations, the defendant bears the burden to prove his counterclaims or defenses.
While one party has the burden to prove a particular fact in issue, the other has the burden to prove another fact. So, only one party has the burden to prove a given fact.
As, 'A' claims damages from 'B' for negligence that caused a road accident involving their cars. 'A' has to prove that the collision that happened between the two cars was due to 'B's negligence, and he suffered loss. In his counterclaim, 'B' has to prove that the collision occurred due to 'A's negligence, and he suffered loss due to the collision.
So, the issues are different for 'A' and 'B'. In this case, 'A' will not get damages if he fails to prove issues raised by him. 'A's failure does not imply that 'B' will get damages. 'B' may get damages if he proves the issues raised by him.
If the defendant in a criminal case is charged with rape, the prosecution has to prove that the defendant has committed the crime. Once the prosecution proves the charge, the defendant has to prove defenses raised by him against the plaintiff's case. He has to produce enough evidence to prove the same.
This type of transfer of obligation to prove the facts in issue is termed as 'shifting the burden of proof'. If the plaintiff or prosecution fails to establish his/her case with proper evidence, the defendant may petition the court to dismiss the case for failure to meet the required burden of proof.
Burden of Production and Persuasion
The concept of burden of proof has two components - burden of production and burden of persuasion. In order to establish the claims, allegations, charges, or defenses, the parties have to produce proper and sufficient evidence to support and establish the same. They have to use the evidence to persuade and convince the judge/jury to a certain level.
The first component that involves the burden of presenting enough compelling evidence is termed 'burden of production'. The second component that involves the burden of persuading the judge with compelling evidence is termed 'burden of persuasion'.
In short, in order to meet the burden of proof, the party has to produce enough compelling evidence, and convince the judge to a certain standard, so that the decision regarding the issue in fact favors that party. However, it is the judge/jury who decides whether the party has met with the required level of burden of proof.
Different Levels of Burden of Proof
Courts have formulated various measures to control the effect of such persuasion on the jury or judge. So, there are certain legal standards, and these standards are useful for the judge/jury to determine whether a party has succeeded in proving or disproving an issue of fact. The standard may vary with different types of cases.
So, the parties have to prove their part up to that standard or level, so as to satisfy the judge/jury. For example, the prosecutor has to prove each and every element that constitutes the crime of murder, so as to prove that the person accused of murder is guilty.
In criminal proceedings, the prosecution must prove the defendant's guilt, 'beyond a reasonable doubt'. This is the highest standard of proof, which requires the most convincing evidence to prove that the accused is guilty.
The definition of this standard of proof: "The standard that must be met by the prosecution's evidence in a criminal prosecution: that no other logical explanation can be derived from the facts except that the defendant committed the crime, thereby overcoming the presumption that a person is innocent until proven guilty."
In civil cases, the standard of proof is 'preponderance of the evidence', which indicates the greater weight of evidence required to convince a judge to decide in favor of one party or the other.
According to this standard, quality of evidence is more important than the quantity. In other words, more convincing evidence is required to win the case. A party to a civil case can meet this standard if more than 50% of the evidence favors him/her.
A party must produce 'clear and convincing evidence' to prove the issues in fact; in certain types of cases, like probate of wills, child custody, juvenile delinquency, paternity, etc. Probable cause is a standard of proof that is used to determine the legality of arrests, searches, and seizures.
Reasonable suspicion is a lower standard of proof that is used to determine whether it was legal for a law enforcement official to stop and frisk a person briefly. Other standards of proof include substantial evidence, credible evidence, etc.
In short, burden of proof is a legal concept that requires the parties to a case to prove the facts in issue to a certain standard, that may vary with the type of case. These standards are not hard and fast, and may not be applicable in all situations. They are meant to impart fairness while deciding legal disputes.