A crime is a wrongful act that is punishable by the government, as opposed to a tort or breach of contract, which are both penalized by private parties. At all stages of the criminal process- from investigation and arrest to trial and sentencing- an accused individual is entitled to due process rights under the U.S. Constitution. These include the right to an attorney, the presumption of innocence, and the right to a speedy jury trial. These rights are also what distinguish criminal law from civil. A defendant in a civil lawsuit is not entitled to the same protections, because the punishments are different.

In criminal law, a guilty defendant may be punished by either incarceration, a fine paid to the government or restitution to the victim, or in some cases, execution. All crimes come in one of two varieties- felonies, which is any crime that carries a possible sentence of more than one year of incarceration, and misdemeanors, which have a maximum possible sentence of less than one year of incarceration.

All criminal laws contain certain “elements”, which define the crime by breaking it down into distinct acts and required states of mind. In order to be found guilty in a criminal trial, it must be proven that a defendant satisfied all of these elements. In other words, they must have committed all of the acts, and had the required state of mind at the time. If any of the elements is not proven beyond a reasonable doubt, the defendant must be found not guilty. For instance, the crime of murder is the intentional and unjustified killing of another human being. In this statute, “intentional” is the required mental state, and “killing” is the act. So in a hypothetical trial it is proven that a person unjustifiably killed another human being, but not proven that the killing was intentional, the defendant must be found not guilty.