Criminal law covers "public wrongs", or offenses against the public and order. The federal, state, and local governments all define these laws and prosecute people who commit these crimes. Public wrongs range from traffic violations to the most serious offenses such as rape or murder. Those charged with a crime all called "defendants". They are represented by defense attorneys, while the government that charges the defendant is represented by an attorney called a "prosecutor". If you are charged with a crime, you will need representation by an attorney with experience in criminal defense in order to protect your legal rights.
The Constitution of the United States requires the government to follow the due process of law before depriving a person of their life, liberty, or property. Criminal statutes must therefore clearly define all crimes and criminal conduct, and cannot be vague or prevent understanding of conduct prohibited by law. Criminal statutes must define a guilty state of mind (called mens rea) as well as an illegal action (called actus reus). For example, it is not a crime to bump someone on a crowded train, because there was no criminal intent. It is also not a crime to think about harming someone without acting. This requirement also applies to attempted crimes. Conviction requires the defendant to take action to attempt a crime. An experience criminal defense attorney can explain these terms and concepts, and help you to understand the specifics of your situation.