Chief Lake Juvenile Law Lawyer, British Columbia

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.

A trial that ends prematurely and without a judgment, due either to a mistake that jeopardizes a party's right to a fair trial or to a jury that can't agree on a verdict (a hung jury) If a judge declares a mistrial in a civil case, he or she will direct that the case be set for a new trial at a future date. Mistrials in criminal cases can result in a retrial, a plea bargain or a dismissal of the charges.

Circumstances that increase the seriousness or outrageousness of a given crime, and that in turn increase the wrongdoer's penalty or punishment. For example, the crime of aggravated assault is a physical attack made worse because it is committed with a dangerous weapon, results in severe bodily injury or is made in conjunction with another serious crime. Aggravated assault is usually considered a felony, punishable by a prison sentence.

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).

An intent to produce the precise consequences of the crime, including the intent to do the physical act that causes the consequences. For example, the crime of larceny is the taking of the personal property of another with the intent to permanently deprive the other person of the property. A person is not guilty of larceny just because he took someone else's property; it must be proven that he took it with the purpose of keeping it permanently.

A plea entered by the defendant in response to being charged with a crime. If a defendant pleads nolo contendere, she neither admits nor denies that she committed the crime, but agrees to a punishment (usually a fine or jail time) as if guilty. Usually, this type of plea is entered because it can't be used as an admission of guilt if a civil case is held after the criminal trial.

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 well-known term for an Alien Registration Receipt Card. This plastic photo identification card is given to individuals who are legal permanent residents of the United States. It serves as a U.S. entry document in place of a visa, enabling permanent residents to return to the United States after temporary absences. The key characteristic of a green card is that it allows the holder to live permanently in the United States. Unless you abandon your residence or violate certain criminal or immigration laws, your green card can never be taken away. Possession of a green card also allows you to work in the United States legally. Those who hold green cards for a certain length of time may eventually apply for U.S. citizenship. Green cards have an expiration date of ten years from issuance. This does not mean that your permanent resident status expires. You must simply apply for a new card.

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).