What is criminal law?

How offences are graded

• Infractions — minor violations, usually fines only, no jail and often no right to appointed counsel.
• Misdemeanours — punishable by up to a year in county jail in most states.
• Felonies — punishable by more than a year, served in state or federal prison, with lasting consequences for firearms rights, professional licences, housing and immigration status.

What the prosecution has to prove

Almost every offence has two parts: the prohibited act (actus reus) and the required mental state (mens rea) — purposely, knowingly, recklessly or negligently. Strict-liability offences such as many traffic violations are the exception, requiring no mental state at all.

The stages of a case

Arrest or citation, charging, arraignment and plea, bail, discovery, pre-trial motions including motions to suppress evidence, plea negotiation, trial, sentencing, appeal. The overwhelming majority of US cases end in a plea rather than a trial.

Rights that operate throughout

The right to remain silent, to counsel (appointed if you cannot afford one), to confront witnesses, to a jury trial for serious offences, and protection against unreasonable searches and double jeopardy. Silence is not evidence of guilt, and asking for a lawyer is not an admission — both are constitutional rights and invoking them clearly is the standard advice of every defence attorney.

Federal or state

Most prosecutions are state. Federal jurisdiction arises when the offence crosses state lines, targets federal interests or occurs on federal land, and federal sentencing follows its own guidelines with limited parole.