What is Reasonable Doubt?

Reasonable doubt is the traditional standard of proof that must be exceeded to secure a guilty verdict in a criminal case in a court of law.

Key Takeaways

  • Reasonable doubt is the traditional, and highest, standard of proof that must be exceeded to secure a guilty verdict in a criminal case in a court of law.
  • Clear and convincing evidence is somewhat less rigorous as it requires that a judge or jury be persuaded that the facts of the case as presented by one party represent the truth.
  • A preponderance of the evidence is the least rigorous standard as it requires only that one party's case be more persuasive after both parties have presented their cases.

Understanding Reasonable Doubt

The phrase “beyond a reasonable doubt” means that the evidence presented and the arguments put forward by the prosecution establish the defendant’s guilt so clearly that they must be accepted as fact by any rational person.

Under U.S. law, a defendant is considered innocent until proven guilty. If the judge or jury has a reasonable doubt about the defendant’s guilt, the defendant cannot be convicted. Simply put, reasonable doubt is the highest standard of proof used in any court of law. It used exclusively in criminal cases because a criminal conviction could deprive the defendant of liberty or even life. The standard of proof beyond a reasonable doubt is widely accepted around the world. The concept of reasonable doubt is imposed only on criminal cases because the consequences of a conviction are severe.

The concept of reasonable doubt is not explicitly stated in the U.S. Constitution. However, it is one of the basic principles of the U.S. legal system that it is worse to convict an innocent person than to let a guilty person go free. This has been stated many times, including by Benjamin Franklin who famously stated that "It is better that 100 guilty persons should escape than one innocent person should suffer." The person charged is considered innocent until proven guilty. As such, the burden of proof falls upon the prosecution to prove its case beyond a reasonable doubt.

Proof beyond a reasonable doubt is required only in criminal cases because the potential penalties are severe.

Other commonly used standards of proof are "clear and convincing evidence" which is one step above "preponderance of the evidence".

  • Clear and Convincing Evidence - where the judge or jurors have concluded that there is a high probability that the facts of the case as presented by one party represent the truth. The standard of clear and convincing evidence is used in some civil cases. It may appear in some aspects of a criminal case, such as a decision on whether a defendant is fit to stand trial. The language appears in a number of U.S. state laws.
  • Preponderance of the Evidence - where both sides have presented their cases, and one side seems more likely to be true. Most civil cases require a "preponderance of the evidence," as this is a lower standard of proof.

Reasonable Doubt - O.J. Simpson Trial

The 1995 murder trial of O.J. Simpson provides an example of the concept of reasonable doubt in practice. The former football star was accused of the murder of his ex-wife, Nicole Brown Simpson, and her friend, Ron Goldman. There was a substantial amount of incriminating evidence against Simpson, including his DNA at the crime scene and blood in his car.

To counter this mountain of evidence, Simpson assembled a legal “Dream Team” that set about trying to create doubt about his guilt in the jurors’ minds. Their case sought to cast doubt on the validity of the DNA evidence and the integrity of the police officers who investigated the murder.

One of the highlights of the trial occurred in the courtroom when Simpson tried to pull on a bloody leather glove that had been recovered on his property, and showed that his hand could not fit into it. In his closing arguments, lead defense counsel Johnnie Cochran famously declared that “If it does not fit, you must acquit.” Cochran listed 15 points of reasonable doubt in the case. After less than four hours of deliberations, the jury found Simpson not guilty on both counts of murder.

A year later, the families of both victims filed a wrongful death civil lawsuit against Simpson. Based on the lower standard of proof, that of a preponderance of the evidence, the jury found Simpson liable for the deaths and awarded the families $8.5 million in damages.