Street Law: A Course in Practical Law
To win a conviction in a criminal case, the prosecutor must prove beyond a reasonable doubt that the defendant committed the crime with the required intent. The defendant does not have to present a defense, but if he or she does, there are a number of possible defenses available.
No Crime Has Been Committed The defendant may decide to try to prove that (1) no crime was committed, or (2) there was no criminal intent because the act was simply committed by mistake.
Defendant Did Not Commit the Crime When there is confusion or doubt about who committed a crime, the defendant may try to prove that there has been a case of mistaken identity and that he or she was not the person responsible for the crime. Today, DNA testing can sometimes be used to prove whether or not the defendant was responsible. In recent years, some people convicted of crimes have been able to prove their innocence because of this testing.
Defendant Committed the Act, but it Was Excusable or Justifiable Sometimes a criminal act may be considered excusable or justifiable. This type of defense includes self-defense and defense of property and others. The law allows people to use deadly force when their own or someone else's life is in danger. The law also permits people to use reasonable force to protect themselves, their property, and others from harm.
Defendant Committed the Act but Is Not Criminally Responsible In this type of defense, the defendant acknowledges that he or she committed the act but argues that there are reasons the law should not consider the defendant criminally responsible. The law recognizes several reasons that may excuse a defendant from criminal responsibility. These defenses include infancy, intoxication, insanity, entrapment, duress, and necessity.