The term “inference” is used to describe the conclusion a person comes to after evaluating all of the evidence before him. In the legal sense, an inference is made after evidence is presented that proves a “fact” to be true. Another term for an inference is “deductive reasoning.” To explore this concept, consider the following inference definition.

Definition of Inference


  1. A reasonable conclusion one comes to after evaluating all of the evidence at one’s disposal.


Late 16th century          Latin (inferentia)

What is an Inference

An inference is a conclusion a person reaches once he evaluates the evidence presented to him. In other words, if A and B are true, then an inference might be made that C must also be true. Consider the following example of an inference being made in a court of law:

Sally, an attorney, is showing exhibits to the jury during the trial of a criminal case. She shows the jury a photograph of a car that was parked four blocks away from the crime scene. The car bears a license plate that is registered to the defendant. She then shows the jury another photograph showing blood stains, determined to be the blood of the victim, that were found in the very same car and marked by forensics. Because the blood stains were present in a car registered to the defendant, then the logical inference to be made here is that – unless his car was stolen – the defendant was involved in the crime.

Typically, when discussing an example of an inference made in a legal situation, the inference is made by a jury during a trial. Based on the facts presented, the jury can infer whether the defendant is guilty or innocent and hand down an appropriate verdict.

Adverse Inference

An adverse inference is a conclusion that is reached in the absence of evidence. In other words, a jury can reach a conclusion based on the silence of a particular witness in a case, or because a piece of key evidence is missing. An example of adverse inference may be seen when a defendant in a case pleads the Fifth Amendment. Though it is his right to do so, the jury may infer that he is choosing not to testify because he has something to hide, as opposed to simply defending his case.

An adverse inference may also be reached if key evidence is destroyed. The court may instruct the jury to infer that what was contained within the evidence was damning enough to help them make a decision. If it was the prosecution’s evidence that was destroyed, perhaps whoever destroyed the evidence knew of, and was attempting to hide, the defendant’s guilt. Conversely, if the defense’s evidence was destroyed, it may have been destroyed by someone attempting to sabotage their case and see the defendant imprisoned.

Mandatory vs. Permissive Presumption

The term “permissive presumption” refers to an inference that a jury can make if they choose to make it. They have information A, and from that information they may infer information B. They don’t have to make an inference if they don’t want to, though the judge can assure them that such an inference would be permitted. For instance, if the evidence presented in the case before the jury is similar to evidence presented in another well-established case, the jury is permitted to infer the crime that was committed, or who committed it. They can use the information already established in the other case to aid them in their decision.

On the other hand, a “mandatory presumption” is a direction from the judge to the jury that they must make an inference based on the evidence provided to them by the State. While a mandatory presumption is more like an order, a permissive presumption is more like a suggestion. With a permissive presumption, the judge is basically telling the jury “you don’t have to make a decision based on what you’ve heard, but you can if you want to.” With a mandatory presumption, the court is telling the jury they should make a decision based on what they’ve heard.

While it would be expected that a jury would be allowed to make their own inference based on what they’ve heard, a mandatory presumption actually violates due process. Therefore, when a defendant is appealing a decision, it is important for the appeals court to establish whether the jury was directed to make a mandatory presumption at trial, or whether they were permitted to draw their own conclusions.

Consider the following examples, which clarify better the difference between a permissive presumption and a mandatory presumption:

Mandatory Presumption

During a criminal trial, the prosecution shows video footage to the jury wherein the defendant can be seen walking into the store ten minutes before the alleged robbery took place. The defendant has a similar build to that which was described by eyewitness accounts, and he is wearing similar clothes as well.

He is seen on the tape rushing out of the store shortly after the robbery occurred with a bag under his arm. The prosecution argues that the bag contains the stolen money from the register. Based on the evidence presented by the prosecution, the judge orders the jury to presume the defendant is the man who robbed the store.

Permissive Presumption

Here, the prosecution shows the jury the same evidence. However, the judge does not direct the jury to decide, beyond reasonable doubt, that the guilty party is sitting right in front of them. Instead, the judge assures them that they can come to the conclusion that this is their guy if they so choose, but that they don’t have to conclude that he’s guilty based solely on the evidence provided by the prosecution.

The difference here is that the defendant’s rights under due process are not being violated. The prosecution still has work to do. The jury must still be convinced that the defendant is guilty without the judge coming to the prosecution’s aid and ordering a guilty verdict.

Inference Example Involving an Arrest without a Warrant

A good example of an inference being made in a criminal case can be found in 1898’s Joske v. Irvine. Here, Joe Shely, a San Antonio police officer, arrested James Irvine without a warrant. Irvine was held for almost 24 hours in the city prison before being released. Irvine thereafter sued Alexander Joske, his employer, for damages on the grounds of unlawful arrest. Irvine alleged that Joske had either “requested or directed” that Shely carry out the arrest.

When the matter went to trial, the court instructed the jury that the arrest was indeed unlawful. Irvine won and was awarded $250 – a lot of money back in the late 1800s. Joske, of course, appealed the verdict, but the Court of Civil Appeals affirmed it. Joske then brought his case to the Supreme Court of Texas. The question the Supreme Court then faced was: could it be legally inferred that Joske “requested or directed” Irvine’s arrest based on the testimony that had been given at trial?

Ultimately, the Court decided that no, it could not make the inference that Joske had been responsible for Irvine’s arrest based on testimony alone. Specifically, in its decision the Court wrote:

“There is no direct testimony that Joske ‘requested or directed,’ the arrest, and we are of the opinion that such fact cannot be reasonably inferred from the circumstances. ‘An inference is a deduction which the reason of the jury makes from the facts proved.’ [1 Rice on Ev., sec. 36]. If the jury cannot reasonably make the deduction, the law does not authorize it. Upon the whole case, we are of opinion that the probative force of the testimony does not go beyond the point of creating a mere surmise or suspicion that Joske ‘requested or directed’ the arrest, and that therefore, under the principles above discussed, there is not, in legal contemplation, ‘any evidence’ of that fact.”

Related Legal Terms and Issues

  • Defendant – A party against whom a lawsuit has been filed in civil court, or who has been accused of, or charged with, a crime or offense.
  • Due Process – The fundamental, constitutional right to fair legal proceedings in which all parties will be given notice of the proceedings, and have an opportunity to be heard.
  • Evidence – Information presented to a court or jury in proof of the facts, including testimony of witnesses, records, documents, or objects.
  • Forensics – Scientific tests used to detect whether a crime took place.
  • Jury – A group of people sworn to render a verdict in a trial, based on evidence presented.
  • Plea – A defendant’s response to criminal charges or a legal declaration.
  • Trial – A formal presentation of evidence before a judge and jury for the purpose of determining guilt or innocence in a criminal case, or to make a determination in a civil matter.