Burden of Proof

The phrase burden of proof refers to the obligation of a party who initiates a legal action (the “plaintiff”) to prove his or her claims. If that party cannot prove sufficiently that the other party has committed a wrong, whether civil or criminal, he loses. The level or certainty to which the plaintiff must prove his case depends on the type of case. To explore this concept, consider the following burden of proof definition.

Definition of Burden of Proof


  1. The obligation to present evidence to the court or jury to prove one’s case.


1585 or earlier  Latin   semper necessitas probandi incumbit ei qui agit (the necessity of proof always lies with the person who lays charges.”)

What is Burden of Proof

In the U.S. legal system, a person accused of a crime is, by law, considered innocent until proven guilty. In other words, it is assumed that he is innocent, and it is the prosecutor’s responsibility to prove he committed the crime. This benefit of assumption is extended to civil lawsuits as well. When a person files a civil lawsuit, claiming the other party did something wrong that somehow harmed him, he is required to bring enough evidence to convince the judge or jury. The other party does not have to provide evidence that he didn’t do it, though he can submit evidence that contradicts the plaintiff’s evidence.

This requirement that the party bringing a legal action prove his case is referred to as the burden of proof. In a criminal case, burden of proof is on the prosecutor, who must prove, beyond a reasonable doubt, that the defendant committed the crime for which he is charged. This means there is zero doubt that the plaintiff did it. In a civil case, the standard of proof is much lower, with the plaintiff being required only to prove that it is more likely than not that the defendant cause his damages.

Burden of Proof in a Civil Lawsuit

When an individual files a civil lawsuit against someone else, the burden of proof rests on his shoulders. When the parties go to court, they each have an opportunity to tell their side of the story. Of course, if that was all that was needed, nearly every case would end in a “he said / she said” situation. The party who filed the lawsuit, called the “plaintiff,” or the “petitioner,” must prove that the things alleged in the lawsuit are true, and that the other party, called the “defendant,” or the “respondent,” caused harm or damages.

The standard to which the plaintiff must prove his case in a civil lawsuit is quite different from the standard of proof required in a criminal case. In a civil case, it need only be proven by a preponderance of evidence, which means that it is more likely than not that the defendant’s actions caused the plaintiff’s damages. There are some types of civil cases that are considered to be more serious. These cases must be proven by clear and convincing evidence, which means that the evidence presented against the defendant must have a high probability of being true.

For example:

Sarah’s gold necklace disappeared out of her jewelry box, and she suspects her roommate took it. When the roommate, Nora, denies having taken it, then shows up with a new tablet that she couldn’t afford a couple of weeks before, Sarah demands payment for her missing necklace. She files a civil lawsuit against Nora, asking for $750 as reimbursement for the stolen item.

During the trial at small claims court, Sarah cannot provide concrete proof that it was Nora who took her necklace. In fact, Nora tells the judge that there were other people in and out of the apartment the day it went missing. Sarah makes the argument that the necklace was inside her jewelry box, in her locked bedroom, and that Nora was the only person besides herself who had a key to the bedroom. In this example of burden of proof requirement, Sarah convinced the judge that it was more likely than not that Nora took the necklace. She awarded Sarah the value of the necklace.

Burden of Proof in a Criminal Case

In a criminal case, the accused person is by law assumed innocent until the prosecution proves that he is guilty. The burden of proof in a criminal case rests on the prosecution, with no requirement that the defendant prove that he is innocent. The standard to which the prosecution must prove the defendant’s guilt is much higher than in a civil case, as the defendant’s freedom is often at risk. In a criminal matter, the prosecution must prove, beyond a reasonable doubt, that the defendant did the deed.

There are a few circumstances in which a defendant may want to take action in proving his innocence. If the defendant wishes, for instance, to make a claim that he is not guilty by reason of insanity, the burden of proving that he was insane at the time of the crime, rests on the defendant. Claims of duress or self-defense also require the defendant to prove the circumstances.

For example:

A few weeks ago, 19-year old Samuel noticed someone following his 16-year old sister around, after school, in the morning, and even at the mall. His sister was scared, so Samuel started walking her to and from school, and other places she needed to go. A few days later the man approached Samuel when he was alone, and said he wanted Samuel to break into his Uncle’s home and steal some valuable items. When Samuel made it clear he thought the man had lost his mind, the man threatened Samuel’s sister, saying he knows where she lives and goes to school, and all of the places she hangs out, implying she would be harmed if he didn’t cooperate.

Afraid for his sister’s safety, Samuel let himself in to his Uncle’s house while he was at work. He grabbed the items the man demanded, and left. Eventually Samuel was arrested and charged with breaking and entering, and burglary. Samuel pled not guilty, and when the case went to trial, it was the prosecutor’s job to prove that Samuel, without a doubt, committed the crime. After the prosecutor showed some weighty evidence and testimony, Samuel’s attorney began painting a picture of Samuel’s very real fear for his sister’s safety. In this example of burden of proof, Samuel is claiming that, while he did steal the items from his Uncle’s home, he did it under duress.

Burden of Proof Example in Murder Trial

In 1995, former football player O.J. Simpson was charged with the brutal murders of his ex-wife, Nichole Brown Simpson, and her friend, Ronald Goldman. Simpson’s crackerjack team of defense lawyers watched for over six months as the prosecution painted a mural of facts and evidence against Simpson, in an attempt to meet their burden of proof. In the end, a key piece of evidence, the bloody leather glove that had supposedly been worn by Simpson when he committed the murders, proved to be the prosecution’s undoing.

As they sat back while the defense team took over to refute each piece of evidence, and point out inconsistencies in the testimony of various witnesses, the prosecution felt they had effectively laid the groundwork for a successful conviction. When his attorney had Simpson step over to stand right in front of the jury box, then directed him to put on that same glove, the prosecution’s entire case came undone. After laboring for months to meet their burden of proof, that simple act of attempting to pull a glove several sizes too small over Simpson’s hand, introduced doubt that the jury simply couldn’t overcome.

Quite possibly remembering attorney Johnny Cochran’s declaration about the glove, “If it doesn’t fit, you must acquit,” the jury deliberated only four days before declaring O.J. Simpson not guilty on both counts of murder. Although, in this example of burden of proof, the prosecution shouldered their responsibility of proving the case, they failed to meet the standard of proof, which them to prove Simpson’s guilt beyond a reasonable doubt.

The Supreme Court on Burden of Proof

In 1967, 12-year old Samuel Winship was arrested, and charged with breaking into a woman’s locker, stealing over $100 from her purse. In the official charge, the prosecution argued that, had an adult committed the same act, it would be considered larceny. At the time, New York law required that deciding whether or not a juvenile was guilty of a crime be based on a preponderance of evidence. While the prosecution still had the burden of proving that Winship was guilty of the crime, the standard to which he had to prove his assumption was much lower than it would have been for an adult.

Using this lower standard, the court found Winship guilty. His attorney appealed, arguing that, if the prosecution wished to charge the young man with an adult crime, the standard of proof must be that of an adult, which is beyond reasonable doubt.  Both the appellate court, and the New York Supreme Court denied Winship’s appeal based on his due process rights. His case was then taken before the U.S. Supreme Court.

In a split 5-3 decision, the Court ruled that the State has the burden of proving guilt in a criminal matter beyond a reasonable doubt, for both adults and juveniles. While making decisions by a preponderance of evidence is commonly used in civil cases, the possibility that the fate of a defendant might be decided wrongly, based on errors in presentation of facts, is too great. In any case in which loss of liberty is a possibility, the due process standard of proof beyond a reasonable doubt must apply, regardless of the defendant’s age.

Related Legal Terms and Issues

  • Civil Lawsuit – A lawsuit brought about in court when one person claims to have suffered a loss due to the actions of another person.
  • Duress – Threats, intimidation, or bullying intended to force someone to do something.
  • Guilty – Having committed an offense, violation, crime, or wrong, especially against penal or moral law.
  • Innocent – Free from guilt or sin; not guilty of a crime or offense.
  • Prosecutor – A government attorney tasked with presenting the state’s case against a defendant in a criminal case.