“Affirmative Defense” in Criminal Law – What is it?

Posted on February 28, 2022

In criminal cases, an affirmative defense is a legal defense to a crime that the defendant bears the burden of proving. Rather than challenging evidence that proves the elements of the crime, an affirmative defense often claims that the offense was justified or excusable. Some examples of affirmative defenses are insanity, duress, and entrapment.

What is an affirmative defense?

An affirmative defense is a type of defense strategy in a criminal case. Affirmative defenses tacitly admit that the defendant committed the crime, but argue that it was somehow excusable or justified. Unlike other defense strategies, affirmative defenses put the burden of proof on the defendant. In order to succeed with an affirmative defense, the defendant has to prove the claim with evidence, often by a preponderance of the evidence.

Affirmative defenses are different from other criminal defense strategies. Other criminal defense strategies aim to prevent law enforcement from proving an essential element of the crime.

An example of this difference can be seen in a defense of a charge for assault. To prove a case of assault, prosecutors generally have to show that the defendant willfully used force on someone else.

An example of a non-affirmative defense in this situation is lack of the requisite intent. It is up to the district attorney to prove, beyond a reasonable doubt, that the defendant acted willfully. A criminal defense attorney can raise a lack of intent defense by challenging the prosecutor’s case that the defendant’s conduct was willful. This often involves evidence that the defendant only accidentally used force on the alleged victim.

Arguing that the defendant acted out of duress is an affirmative defense in this case. It does not challenge the prosecutor’s case that the defendant willfully used force on someone else. Instead, the defense claims that the assault was done because the defendant had been put under substantial duress by someone else. The defendant has to back this claim up with proof that, for example, someone else threatened to kill him or her if the assault was not committed.

What are some examples?

Some common affirmative defenses that are recognized by criminal law are:

• insanity,
• entrapment,
• intoxication,
• duress,
• mistake of fact,
• the statute of limitations, and
• necessity.

All of these defenses require the defendant to present sufficient evidence to support the defense. A criminal defense lawyer can help.

Is it constitutional to require the defendant to raise evidence of innocence?

Affirmative defenses are controversial because they require the defendant to present evidence of their innocence. However, the Supreme Court of the United States has said that this does not violate the Due Process Clause of the U.S. Constitution. The Due Process Clause only requires law enforcement to prove all of the elements of the crime beyond a reasonable doubt.¹ Requiring the defendant to present evidence for an affirmative defense is not unconstitutional because it does not challenge any of the elements of the offense.²

In some cases, though, it can be unclear whether a defense strategy focuses on an element of the offense or not.

For example: Gerald is accused of first-degree murder. An element of this crime is that the defendant acted with malice aforethought. Gerald raises the defense of voluntary intoxication, arguing that he was too drunk to act with malice aforethought. Intoxication is normally an affirmative defense that the defendant has the burden of proving. In this case, though, it challenges an element of the crime. Once the defendant produces enough evidence to potentially make a juror doubt the requisite intent, the burden shifts to the prosecutor to disprove the intoxication defense.³

Is self-defense an affirmative defense?

Whether self-defense is an affirmative defense or not depends on the state.

In the vast majority of the states, it is not an affirmative defense to criminal charges. In these states, the defendant does not have the burden of proving that they acted in self-defense or in defense of others. Instead, defendants generally only have to claim self-defense. The burden of proof then lies with the prosecutor to prove that the defendant was not acting in self-defense.

This is the rule in states like California⁴ and New York.⁵

Very few states require the defendant to prove that they acted in self-defense. In 2019, Ohio was one of the last to declare that self-defense was not an affirmative defense.⁶

When do affirmative defenses have to be raised in a criminal case?

The rules of criminal procedure generally requires defendants to raise an affirmative defense very early in the case in order to use it during trial. It often has to be raised during the preliminary hearing, or even at the arraignment. Some states require that defendants provide written notice of their intentions to raise an affirmative defense to prosecutors.

Defendants have to state their intention to raise an affirmative defense early because the defense will alter how the case proceeds. It puts law enforcement on notice so it can prepare its case without being surprised.

If defendants do not state their intention to raise an affirmative defense early enough, it is treated as a waiver of their right to do so. If they try to raise an affirmative defense later on, the court will prevent them from making it.

What is the burden of proof that the defendant has to meet?

Generally, affirmative defenses need to be proven by a preponderance of the evidence. A preponderance of the evidence is often defined as being satisfied with more than 50 percent certainty. This is a much easier standard to meet than the beyond a reasonable doubt measure.

However, raising an affirmative defense can be risky. Focusing on an affirmative defense generally means not challenging the prosecutor’s evidence regarding the essential elements of the crime. This can admit culpability and criminal liability in the hope that the judge or jury sees the offense as excusable or justifiable.

The best way to decide how to proceed is to establish an attorney-client relationship with a criminal defense lawyer from a reputable law firm.

Are there affirmative defenses in civil claims?

Yes, there are also affirmative defenses in civil lawsuits. These are raised by the defendant in an attempt to avoid civil liability in the plaintiff’s claim or cause of action. Some of the most common are:

• comparative or contributory negligence,
• laches,
• estoppel,
• duress,
• assumption of risk, and
• res judicata.⁷

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