Attorney at Law

Reasonable Doubt

James Parker
March 7, 2022
Last reviewed by
October 18, 2023

What Is Reasonable Doubt?

Reasonable doubt is a standard of proof required to convict a defendant in a criminal trial. It is one of several burdens of proof used in the legal system of the U.S.

Burdens of proof are not strictly defined and can be open to interpretation by the individual. Instead, general ideas are presented and attorneys and judges further clarify for the jury how sure they must be.

Beyond a reasonable doubt is the highest standard of proof. The reasonable doubt standard puts the burden of proving guilt on the prosecution completely. This means that the defense may not need to say anything at all if the prosecution has not presented enough evidence to meet their burden of proof and the defendant will be found innocent.

While there is no strict definition on how sure someone needs to be in order to meet the “beyond a reasonable doubt” standard, the burden assumes that no reasonable person would have any doubts about the defendant’s guilt. In numerical terms, attorneys may throw out figures between 95% and 99% sure of the defendant’s guilt.

This means that the evidence presented must collectively offer no other rational or logical explanation other than that the defendant is guilty. Judges may also say that beyond a reasonable doubt means that no reasonable person would ever question the defendant's guilt, this can sometimes be paired with the idea of “moral certainty.”

Key Takeaways

  • Reasonable doubt is the standard of certainty required for a jury to convict a criminal defendant. 
  • Reasonable doubt creates the largest burden of proof on the prosecution who must prove that the defendant is guilty beyond a reasonable doubt.
  • If a reasonable person would have reason to question whether the defendant is truly guilty, then the reasonable doubt threshold has not been cleared.
  • If you are charged with a DUI, an experienced DUI attorney may be able to improve the outcome of your case by leveraging experience and expert testimony to remove certainty beyond a reasonable doubt.

Reasonable Doubt and Driving Under the Influence (DUI) Charges

Beyond a reasonable doubt is the highest standard of evidence that the U.S. justice system has. The prosecutor, on behalf of the government, must prove that a defendant is guilty with enough evidence and proof that no reasonable person would harbor any doubt about delivering a guilty verdict.

This places the advantage in the hands of the defendant. Reasonable doubt means that it is not enough to convict the defendant on mere belief that they are guilty. The prosecutor must therefore build an insurmountable case against the defendant consisting of physical evidence, witness testimony, even expert witnesses.

This also makes the challenging of this evidence vital. By proving, for example, that the arresting officer is not able to effectively recall the night of the arrest, they can call the testimony of that witness into doubt. With that doubt planted, the jury may not be able to believe everything the officer says, especially if their testimony contradicts some physical evidence already present on the record.

Expert witnesses who can dispute the efficacy of physical evidence can also be pivotal. An expert who can challenge the results of a breathalyzer by explaining the error rates or miscalibration of the device in question can then cast doubt over that piece of evidence.

The design of these strategies is not merely to be needlessly skeptical. By showing how errors could have occurred, how misconduct was present, or how evidence was mishandled, those seeds of doubt can take root in the mind of the jury and they may no longer feel that the case is as black and white as they otherwise may have. That lack of surety then fails to meet the standard of beyond a reasonable doubt and the defendant stands a far better chance of being found not guilty.

Bottom Line

Beyond a reasonable doubt is the highest burden of proof required, but that doesn’t mean prosecutors aren’t up to the task. If you have been charged with a DUI you should contact a DUI attorney to ensure the best possible outcome for your case.

An experienced DUI attorney can leverage trial tactics, good motion practice, experience, and expert witnesses to help defend your innocence. These tools can be used to leverage against the prosecutor’s arguments and push the evidence and testimony back within the bounds of reasonable doubt, offering you a better outcome for your case.

Ask a Lawyer

Ask your own question and get advice from expert attorneys
Ask Question

Featured DUI Law Lawyers

Issa Law, LLC

13 years in practice
Auto Accidents, Bicycle Accidents, Criminal Defense, DUI Law, Motorcycle Accidents
View Profile

Ianuario Law

16 years in practice
Auto Accidents, DUI Law, Medical Malpractice
View Profile

The Clardy Law Firm, P.A.

28 years in practice
Auto Accidents, DUI Law
View Profile


1 years in practice
Insurance Law, Personal Injury
View Profile

Issa Law, LLC

13 years in practice
Auto Accidents, Bicycle Accidents, Criminal Defense, DUI Law, Motorcycle Accidents
View Profile

Law Office of Tal Rubin, PC

22 years in practice
Auto Accidents, Personal Injury
View Profile


Are you looking for an attorney? Do you have questions about a legal case you are facing? Contact us now and we will put you in touch with a lawyer for free.
Attorney At Law is changing how clients connect with lawyers. By providing an innovative platform to lawyers who want to expand their practice’s reach, AAL is bringing law practices into the future.
6142 Innovation Way
Carlsbad, California 92009
Some of the content of this website may be considered attorney advertising under the rules of certain jurisdictions. The information on this website is for general information purposes only. Nothing on this site should be taken as legal advice for any individual case or situation. This information is not intended to create, and receipt or viewing does not constitute an attorney-client relationship.
crossmenuchevron-upchevron-down linkedin facebook pinterest youtube rss twitter instagram facebook-blank rss-blank linkedin-blank pinterest youtube twitter instagram