The Presumption of Innocence: Definition & Overview

Instructor: Brittany McKenna

Brittany is a licensed attorney who specializes in criminal law, legal writing, and appellate practice and procedure.

You have probably seen a television show or movie that depicts a trial. In this lesson, you will learn more about why trials work the way they do, including the important concepts on presumption of innocence and burden of proof.

Presumption of Innocence

'Ei incumbit, probatio qui dicit, non qui negat.' Unless you're a Latin scholar, you've probably never heard this sixth century phrase. Roughly translated, this ancient phrase means: 'The burden of proof is on he who declares, not on he who denies.' In other words, the maxim describes the concept of presumption of innocence.

The term 'presumption' means the acceptance of something as true. In the legal context, the phrase presumption of innocence means that we accept a defendant's innocence, or, stated differently, that we assume a defendant is innocent when a trial begins. This means that, in trial, a criminal defendant is under no obligation to prove his innocence. Therefore, the government (also known as the prosecution) bears the burden of proving the defendant's guilt beyond a reasonable doubt.

The phrase 'innocent until proven guilty' was first coined in the late 1700's by English lawyer Sir William Garrow. Garrow believed that accusations of criminal conduct should be subjected to vigorous testing in a court of law. The presumption of innocence is (more or less) a formalization of Garrow's famous phrase.

Burden of Proof

In order to prove guilt, the prosecution must meet an evidentiary threshold known as the burden of proof. The prosecution's burden in a criminal trial is two-fold: first, it must prove that the crime alleged was actually committed; and second, that the person accused of committing the crime (the defendant) was the person who actually committed the crime.

Imagine you are accused of robbing a store clerk at knife point. You are arrested, charged, and brought to trial. The prosecution must prove all elements of the crime of robbery. The prosecution produces the testimony of the store clerk and a shopper who witnessed the attack. Both the store clerk and shopper identify you as the attacker. They both also say that a knife was used in the attack. The prosecution also produces a knife that they found in your pocket when they arrested you. In a police interview (a recording of which was played for the jury), you admit to owning the knife.

The prosecution has produced a good amount of compelling evidence proving your involvement in the crime. Not only were you identified by two witnesses as the perpetrator, a weapon that matches the description of the weapon used in the robbery was found in your pocket. The prosecution has likely met its burden of proof because a reasonable jury would believe that the crime was committed, and that you committed the crime.

Standards of Proof

The amount of proof needed to convict the defendant depends on the standard of proof in a given case. This means that, in order to prove a defendant committed a crime, a certain amount of proof is necessary. For example, if only one witness had testified that he saw you going into the store on the night it was robbed, that alone would probably not convince a jury that you were guilty. Some evidence was provided, but not enough to meet a reasonable standard of proof.

To unlock this lesson you must be a Member.
Create your account

Register to view this lesson

Are you a student or a teacher?

Unlock Your Education

See for yourself why 30 million people use

Become a member and start learning now.
Become a Member  Back
What teachers are saying about
Try it risk-free for 30 days

Earning College Credit

Did you know… We have over 200 college courses that prepare you to earn credit by exam that is accepted by over 1,500 colleges and universities. You can test out of the first two years of college and save thousands off your degree. Anyone can earn credit-by-exam regardless of age or education level.

To learn more, visit our Earning Credit Page

Transferring credit to the school of your choice

Not sure what college you want to attend yet? has thousands of articles about every imaginable degree, area of study and career path that can help you find the school that's right for you.

Create an account to start this course today
Try it risk-free for 30 days!
Create an account