A criminal offense is any act, or failure to act, that violates a law enacted by a federal, state, or local government and is punishable by that government. The government-imposed punishment is what separates a crime from a private dispute. Offenses run across a wide range of severity: under federal law alone, they stretch from infractions carrying no jail time to Class A felonies punishable by life in prison or death.1Office of the Law Revision Counsel. 18 U.S.C. 3559 – Sentencing Classification of Offenses And the consequences keep going after the sentence ends, touching employment, voting, and the right to own a firearm.
What the Government Has to Prove
For most crimes, a prosecutor has to prove two things happened together: a prohibited act and a guilty mental state. Lawyers call them actus reus and mens rea. If either piece is missing, the case generally fails.
The Act
The act has to be voluntary conduct the law forbids. A muscle spasm or something you do while unconscious doesn’t count, because you had no control over the movement. The “act” can also be a failure to act, but only when the law specifically requires you to do something. A parent who doesn’t feed a child, a lifeguard under contract who ignores a drowning swimmer, or someone who takes on care of another person and then abandons them can all face criminal liability for doing nothing.
The Mental State
The mental-state requirement keeps the system from punishing people for genuine accidents. Different crimes demand different levels of intent. The Model Penal Code, which shaped criminal statutes across the country, sorts culpability into four tiers:
- Purposely: you set out to cause the result. Planning and carrying out a robbery is the clearest case.
- Knowingly: you didn’t necessarily want the result, but you were practically certain your conduct would cause it.
- Recklessly: you knew about a serious risk and ignored it. Firing a gun into a crowd without aiming at anyone is reckless because the danger is obvious.
- Negligently: you should have been aware of a substantial risk but weren’t. This is the lowest tier, and it comes up where carelessness crosses from civil fault into criminal territory.
Beyond the act and the mental state, the prosecution has to show causation and concurrence. Causation means the defendant’s conduct actually produced the harm. Concurrence means the guilty mind existed at the same moment as the act. If someone accidentally breaks a window and only later decides they’re glad it happened, the after-the-fact satisfaction doesn’t convert the accident into a crime.
When Intent Doesn’t Matter: Strict Liability
Some offenses skip the mental-state requirement entirely. Strict liability crimes hold you responsible based on what you did, regardless of what you knew or intended. Statutory rape is the classic example: in most states, a defendant who genuinely believed the other person was old enough to consent is still guilty. Drug possession works the same way in many jurisdictions. Most traffic violations fall into this category too, which is why “I didn’t know I was speeding” doesn’t get you out of the ticket.
Strict liability tends to show up in two places: regulatory offenses where the legislature wants strong compliance incentives (selling alcohol to a minor, violating food safety rules) and conduct the legislature considers so dangerous that even an honest mistake shouldn’t be a defense. These crimes are the main exception to the general rule that criminal liability requires a guilty mind.
How Criminal Law Differs From Civil Law
The practical difference comes down to who brings the case and what they’re trying to accomplish. In a criminal case, the government prosecutes you for violating a public law, and the goal is punishment, deterrence, and public safety. In a civil case, a private person or company sues another to recover money or force specific action, and the goal is compensation.
The proof standards reflect the stakes. A criminal conviction requires proof “beyond a reasonable doubt,” meaning the evidence must leave the jury firmly convinced of guilt. The Supreme Court has held that this high bar is constitutionally required by the Due Process Clause.2Justia Law. In Re Winship, 397 U.S. 358 (1970) Civil cases use “preponderance of the evidence,” which simply means the claim is more likely true than not.
That gap explains why someone can be acquitted of a crime and still lose a civil lawsuit over the same conduct. A criminal acquittal means the government couldn’t meet its burden; it doesn’t mean the conduct didn’t happen.
Outcomes differ too. Criminal convictions can bring incarceration, fines, probation, community service, or restitution. Civil judgments typically involve monetary damages, court orders to do or stop doing something, or contract enforcement.
Severity Classes: Felony, Misdemeanor, Infraction
How a crime is classified determines where you’re tried, how long you could spend in custody, and how the conviction affects your life afterward. Federal law breaks offenses into three tiers.
Felonies
Felonies are the most serious offenses and carry potential prison sentences of more than one year. Federal law divides them into five classes. A Class A felony is punishable by life in prison or death. Class B carries a maximum of 25 years or more. Class C ranges from 10 to less than 25 years, Class D from 5 to less than 10 years, and Class E covers anything above one year but under five.1Office of the Law Revision Counsel. 18 U.S.C. 3559 – Sentencing Classification of Offenses Most states use similar systems, though the labels and ranges vary.
Misdemeanors
Misdemeanors are less serious offenses punishable by up to one year of incarceration, usually in a local or county jail rather than a state prison. Federal law splits misdemeanors into three classes: Class A (six months to one year), Class B (30 days to six months), and Class C (five to 30 days).1Office of the Law Revision Counsel. 18 U.S.C. 3559 – Sentencing Classification of Offenses Sentences often include fines, probation, or community service instead of or alongside jail time. Petty theft, simple assault, and disorderly conduct are typical.
Infractions
Infractions sit at the bottom. Under federal classification, an infraction carries five days or less of imprisonment, or none at all.1Office of the Law Revision Counsel. 18 U.S.C. 3559 – Sentencing Classification of Offenses In practice, most are punishable only by a fine. Speeding tickets and parking violations are the everyday examples.
Types of Crime by the Harm Involved
Crimes are also grouped by the kind of harm they target. Crimes against persons involve direct harm or threats to an individual: assault, robbery, homicide. Property crimes target belongings rather than people and include theft, burglary, arson, and vandalism. The dollar value of stolen property often decides whether a theft is charged as a misdemeanor or a felony, and the threshold varies widely by state.
White-collar crimes involve fraud or deception for financial gain. Embezzlement, insider trading, identity theft, and tax fraud all fit here. These offenses frequently cross state lines, which can trigger federal jurisdiction. Federal cybercrime law covers unauthorized access to protected computers, computer fraud, transmitting malicious code, and using computers for extortion.3Office of the Law Revision Counsel. 18 U.S.C. 1030 – Fraud and Related Activity in Connection With Computers
Inchoate crimes punish conduct that didn’t result in a completed offense. Attempt, conspiracy, and solicitation all target behavior aimed at committing a crime that was either interrupted or never carried out. Drug offenses and impaired driving are sometimes called statutory crimes because they’re defined entirely by legislation rather than common-law tradition, and they don’t always involve a specific identifiable victim.
State Crimes vs. Federal Crimes
Most crimes in the United States are prosecuted under state law. Each state writes its own criminal code, and local police, sheriffs, and state prosecutors handle the vast majority of cases in state courts. Murder, assault, theft, drug possession, and drunk driving are overwhelmingly state matters.
Federal jurisdiction kicks in when conduct violates a specific federal statute. That usually means the offense crossed state lines, happened on federal property, targeted a federal interest, or involved a federal agency. Drug trafficking networks, counterfeiting, large-scale fraud, and crimes on military bases are common federal cases. The FBI investigates broad categories of federal offenses, the DEA focuses on drug enforcement, and the ATF handles firearms and explosives.4Federal Bureau of Investigation. How Does the FBI Differ From the DEA and ATF U.S. Attorneys prosecute these cases in federal court.5Federal Bureau of Investigation. A Brief Description of the Federal Criminal Justice Process
Some conduct violates both state and federal law at the same time. A bank robbery, for example, is a state crime and potentially a federal one. Both governments can prosecute. The Supreme Court confirmed in 2019 that doing so doesn’t violate double jeopardy, because each sovereign enforces its own distinct set of laws.6Supreme Court of the United States. Gamble v. United States In practice, federal and state prosecutors often coordinate to avoid duplicating effort, but the legal authority for both to proceed exists.
What a Conviction Costs After the Sentence
The sentence itself (prison, fines, probation) is only the beginning. A criminal record, especially a felony, triggers consequences that can outlast the formal punishment by years or decades.
Firearms
Federal law prohibits anyone convicted of a crime punishable by more than one year of imprisonment from possessing firearms or ammunition.7Office of the Law Revision Counsel. 18 U.S.C. 922 – Unlawful Acts The ban also covers people convicted of misdemeanor domestic violence, fugitives from justice, and several other categories. Restoring firearm rights after a felony generally requires a pardon or a formal restoration of civil rights.
Voting
Felony disenfranchisement laws vary dramatically across the country. A small number of states allow incarcerated people to vote. Others restore voting rights immediately upon release. Many require completion of the full sentence, including parole and probation, before eligibility returns. Some states strip voting rights indefinitely for certain felonies, requiring a governor’s pardon or a separate petition process.8U.S. Commission on Civil Rights. Collateral Consequences – The Crossroads of Punishment, Redemption, and the Effects on Communities
Employment and Housing
A criminal record shows up on background checks, and employers in many industries run them routinely. Federal law requires employers who use a background reporting company and decide not to hire you based on the results to give you a copy of the report and a summary of your rights before the decision becomes final.9Federal Trade Commission. Employer Background Checks and Your Rights Many cities and states have adopted laws limiting when employers can ask about criminal history, but the practical impact of a conviction on job prospects remains significant. Housing applications, professional licensing boards, and public benefits programs can all factor in criminal records as well.
Clearing the Record
Most states offer some process for expunging or sealing a criminal record after a waiting period, though eligibility rules, fees, and covered offenses vary widely. At the federal level, expungement options are extremely limited. The Federal First Offender Act allows expungement for certain misdemeanor drug possession offenses committed by people under 21 who successfully complete probation, but no general federal expungement statute exists. For most people with federal convictions, a presidential pardon is the only path to clearing the record.