Geff Juvenile Law Lawyer, Illinois

A minor violation of the law that is punishable only by a fine--for example, a traffic or parking ticket. Not all vehicle-related violations are infractions, however--refusing to identify oneself when involved in an accident is a misdemeanor in some states.

The defendant's formal answer to criminal charges. Typically defendants enter one of the following pleas: guilty, not guilty or nolo contendere. A plea is usually entered when charges are formally brought (at arraignment).

To intentionally destroy, obliterate or strike out records or information in files, computers and other depositories. For example, state law may allow the criminal records of a juvenile offender to be expunged when he reaches the age of majority, to allow him to begin his adult life with a clean record. Or, a company or government agency may routinely expunge out-of-date records to save storage space.

A jury unable to come to a final decision, resulting in a mistrial. Judges do their best to avoid hung juries, typically sending juries back into deliberations with an assurance (sometimes known as a 'dynamite charge') that they will be able to reach a decision if they try harder. If a mistrial is declared, the case is tried again unless the parties settle the case (in a civil case) or the prosecution dismisses the charges or offers a plea bargain (in a criminal case).

Intentionally restraining another person without having the legal right to do so. It's not necessary that physical force be used; threats or a show of apparent authority are sufficient. False imprisonment is a misdemeanor and a tort (a civil wrong). If the perpetrator confines the victim for a substantial period of time (or moves him a significant distance) in order to commit a felony, the false imprisonment may become a kidnapping. People who are arrested and get the charges dropped, or are later acquitted, often think that they can sue the arresting officer for false imprisonment (also known as false arrest). These lawsuits rarely succeed: As long as the officer had probable cause to arrest the person, the officer will not be liable for a false arrest, even if it turns out later that the information the officer relied upon was incorrect.

Latin for 'You have the body.' A prisoner files a petition for writ of habeas corpus in order to challenge the authority of the prison or jail warden to continue to hold him. If the judge orders a hearing after reading the writ, the prisoner gets to argue that his confinement is illegal. These writs are frequently filed by convicted prisoners who challenge their conviction on the grounds that the trial attorney failed to prepare the defense and was incompetent. Prisoners sentenced to death also file habeas petitions challenging the constitutionality of the state death penalty law. Habeas writs are different from and do not replace appeals, which are arguments for reversal of a conviction based on claims that the judge conducted the trial improperly. Often, convicted prisoners file both.

The mental component of criminal liability. To be guilty of most crimes, a defendant must have committed the criminal act (the actus reus) in a certain mental state (the mens rea). The mens rea of robbery, for example, is the intent to permanently deprive the owner of his property.