In homage to its title of “land of the free,” the American justice system presumes someone is innocent until proven guilty. On paper, this makes it necessary for prosecutors to establish a case that leaves no reasonable doubt of guilt. In spite of this, many innocent men and women end up behind bars. 

One often-touted reason for this is the role of circumstantial evidence. Jurors tend to find it convincing and it can become difficult to shake the idea once it is planted. 

Defining circumstantial evidence

According to the New York Courts, circumstantial evidence is an objective fact from which a person may reasonably assume another fact. For instance, an eyewitness might testify that she saw her neighbor pull into his driveway at 10 p.m. Then, at midnight, she heard an engine start outside and noticed his car was now missing from the driveway. She might, therefore, reasonably infer that he left the property by or before midnight. 

Understanding the treatment of circumstantial evidence

New York does not treat circumstantial evidence as less important or carrying less weight than direct evidence. In fact, prosecutors might use both directly observed and inferred evidence to prove the accused person’s guilt. This makes it especially important for the accused not to discount circumstantial evidence. 

UC Hastings Law school further confirms that many convictions arise from only circumstantial evidence. For innocent parties, there is some good news. Studies find that while direct evidence led to 69% of known wrongful convictions, circumstantial evidence contributed to only 9%. One explanation for this is that people often accept direct evidence without considering alternative explanations, while circumstantial evidence provokes deeper thought.