Preble Juvenile Law Lawyer, New York

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 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 burden of proof that the prosecution must carry in a criminal trial to obtain a guilty verdict. Reasonable doubt is sometimes explained as being convinced 'to a moral certainty.' The jury must be convinced that the defendant committed each element of the crime before returning a guilty verdict.

Punishment in a criminal case. A sentence can range from a fine and community service to life imprisonment or death. For most crimes, the sentence is chosen by the trial judge; the jury chooses the sentence only in a capital case, when it must choose between life in prison without parole and death.

A formal investigation -- governed by court rules -- that is conducted before trial. Discovery allows one party to question other parties, and sometimes witnesses. It also allows one party to force the others to produce requested documents or other physical evidence. The most common types of discovery are interrogatories, consisting of written questions the other party must answer under penalty of perjury, and depositions, which involve an in-person session at which one party to a lawsuit has the opportunity to ask oral questions of the other party or her witnesses under oath while a written transcript is made by a court reporter. Other types of pretrial discovery consist of written requests to produce documents and requests for admissions, by which one party asks the other to admit or deny key facts in the case. One major purpose of discovery is to assess the strength or weakness of an opponent's case, with the idea of opening settlement talks. Another is to gather information to use at trial. Discovery is also present in criminal cases, in which by law the prosecutor must turn over to the defense any witness statements and any evidence that might tend to exonerate the defendant. Depending on the rules of the court, the defendant may also be obliged to share evidence with the prosecutor.

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.

The crime of operating a motor vehicle while under the influence of alcohol or drugs, including prescription drugs. Complete intoxication is not required; the level of alcohol or drugs in the driver's body must simply be enough to prevent him from thinking clearly or driving safely. State laws specify the levels of blood alcohol content at which a person is presumed to be under the influence. Also called driving while intoxicated (DWI and drunk driving).

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.