A crime is an act or omission of an act that violates public rulesand regulations. Criminal laws in the United States were enacted tomaintain safety and security and ensure the citizens enjoy theirliberties by prohibiting or regulating certain acts. People whoviolate criminal laws face fines, penalties or imprisonment, ordeath, in certain jurisdictions. Criminal laws, just like almost allother laws, originated with common law and its interpretation, andthe development of these interpretations through the years. Specificincidents, in both national and state arena, also drive legislatorsinto formulating new rules and regulations to address theseincidents.
How a crime is defined and what is considered a crime differs fromone state to another's penal code. A state's penal code isaccompanied with enabling rules and regulations. There are alsofederal crimes and federal criminal laws govern these crimes. Fromthe criminal rules and regulations are created law enforcementagencies, such as the police in the state level, and the FederalBureau of Investigation in the federal level, to make sure criminallaws are not violated. The U.S. Constitution, through the Bill ofRights, is the primary law of the land that limits how criminal lawsshould be applied.
A crime is jurisdiction-specific, which means the law where the crimeis committed governs that crime. It follows that jurisdiction remainswhere the crime was committed. One of the issues that make criminallaw a turf only for experts is the differences among criminal laws indifferent jurisdictions. More than 50 states and territories comprisethe United States. Add to that the federal criminal law that governsfederal crimes, and the crimes committed in other jurisdictionsconsidered to be American jurisdictions, such as a ship, an aircarrier, or an embassy. Jurisdiction, thus, becomes a complicatedmatter when a crime in one state may not be a crime in another.Jurisdiction becomes more complicated when a crime is both a statecrime and a federal crime, resulting to overlapping jurisdiction.
Legal research work in criminal cases is exhaustive. Jurisdictiondetermines whether a precedent is binding. An appellate court'sdecision is often the only decision that can create precedents. Thesedecided upon cases are used by criminal law attorneys to boost theirarguments or strengthen their opponent's arguments, so much of theirlegal work is trying to find applicable and strong precedents.
There are numerous crimes, and each crime is specifically definedsuch that the difference between one crime and another may be amatter of a single word. Before an act or an omission is considered acrime, the prosecutor must first establish several elements. Theseelements must be countered upon by the defendant's attorney such thatthe defendant will be found to not have committed the crime or willbe found to have committed a crime with an accompanying lesserpenalty. Arguing against the elements of a crime is a tedious matteras prosecutors and law enforcement agencies, who produce theevidence, are equipped with sophisticated evidence-gatheringmachinery.