Emma Felony Lawyer, Illinois

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.

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 name of the document, sometimes called a criminal complaint or petition in which a prosecutor charges a criminal defendant with a crime, either a felony or a misdemeanor. The information tells the defendant what crime he is charged with, against whom and when the offense allegedly occurred, but the prosecutor is not obliged to go into great detail. If the defendant wants more specifics, he must ask for it by way of a discovery request. Compare indictment.

Latin for 'we shall no longer prosecute.' At trial, this is an entry made on the record by a prosecutor in a criminal case stating that he will no longer pursue the matter. An entry of nolle prosequi may be made at any time after charges are brought and before a verdict is returned or a plea entered. Essentially, it is an admission on the part of the prosecution that some aspect of its case against the defendant has fallen apart. Most of the time, prosecutors need a judge's A1:C576 to 'nol-pros' a case. (See Federal Rule of Criminal Procedure 48a.) Abbreviated 'nol. pros.' or 'nol-pros.'

The killing of one human being by the act or omission of another. The term applies to all such killings, whether criminal or not. Homicide is considered noncriminal in a number of situations, including deaths as the result of war and putting someone to death by the valid sentence of a court. Killing may also be legally justified or excused, as it is in cases of self-defense or when someone is killed by another person who is attempting to prevent a violent felony. Criminal homicide occurs when a person purposely, knowingly, recklessly or negligently causes the death of another. Murder and manslaughter are both examples of criminal homicide.

A document issued by a judge or magistrate that authorizes the police to arrest someone. Warrants are issued when law enforcement personnel present evidence to the judge or magistrate that convinces her that it is reasonably likely that a crime has taken place and that the person to be named in the warrant is criminally responsible for that crime.

A type of behavior that is has been defined by the state, as deserving of punishment which usually includes imprisonment. Crimes and their punishments are defined by Congress and state legislatures.

A peace officer for a particular geographic area -- most often a rural county -- who commonly has the power to serve legal papers, arrest lawbreakers and keep the peace. Depending on the state, a constable may be similar to a marshal or sheriff.