Consent as a Defense

Fundamentals of Criminal Law by Adam J. McKee

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Consent by the victim can also form the basis of a justification defense to criminal conduct.  Consent is most commonly used as a defense to sex crimes such as rape, and lack of consent is a criminal element of most sexual offenses that must be proven beyond a reasonable doubt.  In the case of physical harms incurred during participation in contact sports such as boxing and football, it is assumed that players consented to the harms inflicted on them by the defendant.  Most jurisdictions will not extend the idea of consent to situations where serious bodily harm or death is the likely outcome. Consent is potentially a defense in all cases where the defendant’s consent or approval are elements of the offense being charged.  This covers a very wide swath of criminal laws. Trespassing, for example, requires that the defendant’s presence on the property without the victim’s permission. If the defendant can show that consent was indeed given, then the prosecution’s case has no merit.  

Consent can be a valid defense to a crime only if the victim chooses to render it. Thus it must be proffered knowingly and voluntarily, or it is ineffective. Under the Model Penal Code, consent is ineffective if “it is given by a person who is legally incompetent to authorize the conduct…it is given by a person who by reason of youth, mental disease or defect or intoxication is manifestly unable to make a reasonable judgment…it is induced by force, duress or deception.”  The legal idea of knowingly giving consent means that the victim fully understood the nature of the act and the potential harm that could come from it. In general, consent is not knowing if it is given by an individual who is too young or who is mentally incompetent.  Consent is often removed as a defense when the crime is defined in terms of the victim’s age or mental incompetence, such as with statutory rape.  It is no defense to statutory rape that the victim consented. The logic is that young girls do not have the capacity to fully appreciate the nature and potential consequences of sexual acts.

Consent must also be voluntary.  In this context voluntary refers to the alleged victim’s free will in making the decision to consent to the conduct of the defendant.  If something removes the capacity of free will, then any consent will be invalid. Most states hold that consent is not voluntary if it is induced by force, the threat of force, or trickery.   In many states, intoxication can be a barrier to valid consent because an intoxicated person cannot knowingly consent.  

Some jurisdictions, such as the ones that have adopted the Model Penal Code, narrowly circumscribed the defense of consent to very few circumstances.   As the Model Penal Code states, “when conduct is charged to constitute an offense because it causes or threatens bodily harm, consent to such conduct or to the infliction of such harm is a defense if: (a) the bodily harm consented to or threatened by the conduct consented to is not serious; or (b) the conduct and the harm are reasonably foreseeable hazards of joint participation in a lawful athletic contest or competitive sport.”  

Key Terms  


References and Further Reading

“Justification: Theory.” Encyclopedia of Crime and Justice.


“Justification: Self-Defense.” Encyclopedia of Crime and Justice.


“Justification: Law Enforcement.” Encyclopedia of Crime and Justice.


“Justification: Necessity.” Encyclopedia of Crime and Justice.


“23 Other States Have ‘Stand Your Ground’ Laws, Too.”  (2012). The Atlantic.  



Coker v. Georgia, 433 U.S. 584 (1977).

Graham v. Connor, 490 U.S. 386, 396–397 (1989).

Tennessee v. Garner, 471 U.S. 1, 11–12 (1985).

U.S. v. Cortez, 449 U.S. 411, 417 (1981).

United States v. Dunn, 480 U.S. 294 (1987)

Modification History

File Created:  07/17/2018

Last Modified:  05/03/2021

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