You have all heard the phrase “it’s not what you know it’s what you can prove,” and the realm of criminal law is no different. Many people accused of crimes generally have some level of criminal culpability but the focus should not be on whether the person committed the offense but rather whether the State can prove the offense beyond a reasonable doubt. To that end, Iowa law provides several defenses to individuals charged with a crime including a general denial, affirmative defenses, and the exclusion of evidence. The type of crime a person is accused of committing and the specific facts of the case often dictate which defense(s) will be applicable to any given situation so it is important to seek competent legal counsel to determine which defenses may apply to any given situation. Iowa law also allows a defendant to present inconsistent defenses to the jury. For example a person can claim intoxication while also claiming they were not at the scene of the crime. Often times however, specific legal defenses are not applicable and the defensive approach needs to focus on excluding certain evidence so that the State is unable to prove the alleged charges.

General Denial

The defense of General Denial is as simple as it sounds; deny the charges and hold the State to their burden of proof. In essence it could be re-named the “prove it” defense. This defense requires no special filings or notice by a defendant and is available on every single charge and case filed against a person. Everyone charged with a crime has the absolute right to require the State to prove the accusations beyond a reasonable doubt. If the State is unable to do so, the verdict must be Not Guilty.

The majority of all trials associated with criminal accusations invoke the General Denial Defense. During this defense it is the defense lawyer’s job to point out inconsistencies in the evidence; elements where the State’s evidence is lacking: what evidence the State did not or could not produce; and from time to time, present evidence on behalf of the defendant that contradicts or minimizes the evidence presented by the State. The “prove it defense” is a tried and true defense to all charges and has been around since the American judicial system has been in existence. It is the classic example of our constitutional protections at work.

Affirmative Defenses Definition

Iowa law also provides certain “affirmative defenses” to those accused of committing crimes which include alibi, insanity, diminished responsibility, intoxication, entrapment, and justification. These are defenses which if successful are bars to criminal liability however they must be raised prior to trial and within forty days following the defendant’s arraignment. Failure to raise these defenses within that time period may present the defense from being used unless “good cause” can be shown for the failure to raise the defense.

What is the Insanity Defense

This is a complete defense to the charged crime and requires the accused to establish the defense by a preponderance of the evidence and can be applied to both general and specific intent crimes. Iowa law follows the M’Naghten rule and provides that a person is insane if at the time the offense was committed the accused was suffering from a diseased or deranged mental condition that renders the person incapable of knowing the nature and quality of the act the person is committing or, incapable of distinguishing between right and wrong. This defense becomes applicable only once the State has proven beyond a reasonable doubt that the accused committed a crime and then the accused must prove that at the time the crime was committed, he or she was legally insane.

Temporary insanity is a sub-category to the insanity defense and can be used if the defendant can provide substantial evidence that the defendant was insane and he/she involuntarily ingested an intoxicant. This defense is not available if the person voluntarily ingested an intoxicant making it a tricky defense to use when a person is suffering from a mental defect and is also using intoxicants.

If a person is found not guilty by reason of insanity, the court must order the person to be committed to a State mental health institute for a complete evaluation to determine whether the defendant is a danger to the defendant’s self or others. The commitment will likely continue as long as the person remains to be a danger to themselves or others.

Diminished Responsibility

Closely related to the defense of insanity is the defense of diminished responsibility. Under this defense, the defendant is unable to form the necessary criminal intent to commit a crime due to a limited capacity to think. This defense differs from insanity because it does not involve an “illness” which distorts the thinking process. In other words, the person may not meet the legal definition of insane but may not be able to for the specific intent to commit a crime. This defense is only available to crimes which require the State to show the accused acted with the “specific intent” to commit the crime and is not available to general intent crimes. Thus, this defense would not be available to someone accused of drunk driving but would be available to someone accused of murder.


The defense of justification is often times also referred to as self-defense, however justification is a much broader defense which includes, self-defense, defense of others, and defense of property. The question often raised in situations where the defense of justification may be applicable centers on whether the amount of force used was reasonable as the law only allows the use of “reasonable force” to protect yourself, another, or property. In order to raise this defense the accused must provide notice within forty days of arraignment and produce substantial evidence that the defense was applicable. If the accused is able to provide substantial evidence the defense is applicable, then the State must prove beyond a reasonable doubt justification did not exist.

Justification is not available if the State is able to prove any of the following: (1) the defendant initiated or continued the incident resulting in injury or (2) the defendant did not believe he was in imminent danger of death or injury and the use of force was not necessary to save him/her or (3) the defendant had no reasonable grounds for such belief or (4) the force used was unreasonable. Moreover, this defense is not available if there was “an alternative course of action” that did not risk life or safety of the actor or a third party. However, the “alternative course of action” doctrine does not apply when in the defender’s dwelling, place of business, or employment.

Whether defending your-self, a third person, or property, the key is going to be whether the amount of force used was reasonable. What force is reasonable is going to in large part depend on the unique facts of each case.


The defense of alibi is probably the least complex of all the affirmative defenses and simply principled on the fact that the accused was not at the scene of the offense but was at another place so as to make his/her commission of the crime impossible. This defense must be raised within forty days of the defendant’s arraignment and must be accompanied by the specific location the defendant claims to have been during the commission of the offense and the names and addresses of the witnesses to be called at trial.


The defense of intoxication is really a form of diminished responsibility and is only applicable when the intoxication “causes a mental disability which makes the person incapable of forming the specific intent” to commit a crime. Thus, it is only available to specific intent offenses and is most commonly used as a defense to reduce the crime of first degree murder to second degree murder. This defense must also be raised within forty days of arraignment but unlike the insanity defense, it does not subject the accused to an evaluation.


Entrapment is probably the most commonly misunderstood defenses provided to an accused person in Iowa and requires the defense to be raised within forty days of arraignment. Entrapment “occurs when a law enforcement agent causes the commission of a crime by using persuasion or other means likely to cause a normally law-abiding person to commit the crime.” Merely providing an opportunity for a person to commit a crime does not constitute entrapment. People who have been accused of buying drugs from an undercover police officer or informant often claim they were entrapped however the officer or informant merely provides an opportunity for the person to buy the drugs and they generally have not persuaded the person to purchase the drugs. One example of where entrapment may occur is if an officer encourages and intoxicated person to come out of a private residence into public and then arrests them for public intoxication.


Compulsion is a rare defense and is used in situations where another person threatens harm to the accused and the accused commits a crime to avoid the threatened harm. In order for this defense to be applicable, the defendant must be in a situation where the defendant was under an unlawful and presently impending threat of serious injury or death in which the defendant did not recklessly or negligently place themselves, and to which there is no reasonable legal alternative to violating the law. However, this defense is not available if a person suffers an injury or harm as a result of the actions of the accused.

Exclusion of Evidence

Many of the above listed defenses are fact specific and therefore may not be applicable to many criminal offenses. If a defense is not applicable the focus needs to shift to looking at whether any statutory or constitutional violations have occurred. If such violations have occurred, the accused will need to file a motion to suppress any evidence obtained in violation of those rights within forty days of arraignment. A successful motion to suppress will exclude any evidence for use at trial which was illegally obtained. Motions to suppress gernally focus on illegal searches and seizures, illegally obtained statements or confessions (i.e. Miranda violations), violations of a person’s right to place telephone calls following arrest, violations of a person’s right to obtain independent chemical testing, and situations where the accused was coerced or involuntarily provided incriminating evidence.

Suffice it to say that not all of the above listed defenses will be available in any given case, however often times at least one of the above listed defenses will have some applicability to a person charged with a crime. Therefore, it is imperative that anyone facing a criminal offense contact qualified legal counsel to determine the best course or strategy for defending your case.