What we call criminal law broadly refers to federal and state laws that make certain behavior illegal and punishable by imprisonment and/or fines. Our legal system is largely comprised of two different types of cases: civil and criminal. Civil cases are disputes between people regarding the legal duties and responsibilities they owe each other. Criminal cases, meanwhile, are charges pursued by prosecutors for violations of criminal statutes.

Criminal Law: History
In the United States, British common law ruled during colonial times. Common law is a process that establishes and updates rules that govern some nations. Once America became an independent nation, it adopted the U.S. Constitution as “the supreme law of the land.” The U.S. continues to employ a common law system, which works in combination with state and federal statutes. As far as criminal laws are concerned, each state has its own penal code which defines what is or is not a crime, the severity of any offense and its punishment.

Felonies and Misdemeanors
Criminal cases are generally categorized as felonies or misdemeanors based on their nature and the maximum imposable punishment. Each state is free to draft new criminal laws, so long as they are deemed constitutional. Thus, what is a crime in one state may not necessarily be a crime in a neighboring state.

A felony involves serious misconduct that is punishable by death or by imprisonment for more than one year. Most state criminal laws subdivide felonies into different classes with varying degrees of punishment. Crimes that do not amount to felonies are typically called misdemeanors. A misdemeanor is misconduct for which the law prescribes punishment of no more than one year in prison. Lesser offenses, such as traffic and parking tickets, are often called infractions.

Police Investigate, Prosecutors File Charges
Many people think that police officers (who investigate crimes) also charge offenders. That is a common misconception. Police gather evidence and sometimes also testify in court. But prosecutors – including district attorneys, United States Attorneys and others – ultimately decide whether a suspect is prosecuted or not.

Criminal Defense Lawyers
A qualified criminal defense attorney is often a crucial advocate for anyone charged with a crime. These attorneys are very familiar with local criminal procedures and laws – some may have even first worked as prosecutors. Most defense lawyers should be able to handle any misdemeanor or low-level crime. But not all lawyers are qualified to handle serious charges. Some courts don’t allow inexperienced attorneys to represent defendants facing capital punishment, for example.

So whether you were arrested for a crime against a person (like assault and battery, rape, or murder), a crime against property (like shoplifting, burglary, or arson), or a drug crime (marijuana possession or cocaine dealing), a criminal defense lawyer can help.