Most crimes require both an act and a guilty state of mind. The guilty state of mind refers to committing the act knowingly, intentionally, or willfully. A few crimes are strict liability offenses that do not require a guilty state of mind, but the act itself constitutes a crime. Every crime is defined by its elements, which must be proven to convict someone. Crimes can also be considered civil wrongs where the victim can sue for damages in addition to criminal charges. Crimes exist at both the state and federal level.