Thomas Juvenile Law Lawyer, Oklahoma

One of the most sacred principles in the American criminal justice system, holding that a defendant is innocent until proven guilty. In other words, the prosecution must prove, beyond a reasonable doubt, each element of the crime charged.

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 legal doctrine that prevents legislators from being sued for actions performed and decisions made in the course of serving in government. This doctrine does not protect legislators from criminal prosecution, nor does it relieve them from responsibility for actions outside the scope of their office, such as the nefarious activities of former Senator Bob Packwood.

A court official usually classified as a peace officer (sometimes as a deputy sheriff, or marshal) and usually wearing a uniform. A bailiff's main job is to maintain order in the courtroom. In addition, bailiffs often help court proceedings go smoothly by shepherding witnesses in and out of the courtroom and handing evidence to witnesses as they testify. In criminal cases, the bailiff may have temporary charge of any defendant who is in custody during court proceedings.

A court appearance in which the defendant is formally charged with a crime and asked to respond by pleading guilty, not guilty or nolo contendere. Other matters often handled at the arraignment are arranging for the appointment of a lawyer to represent the defendant and the setting of bail.

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.

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 situation in which the police detain a person in a manner that, to any reasonable person, makes it clear she is not free to leave. A person can be 'under arrest' even though the police have not announced it; nor are handcuffs or physical restraint necessary. Questioning an arrested person about her involvement in or knowledge of a crime must be preceded by the Miranda warnings if the police intend to use the answers against the person in a criminal case. If the arrested person chooses to remain silent, the questioning must stop.

A serious crime (contrasted with misdemeanors and infractions, less serious crimes), usually punishable by a prison term of more than one year or, in some cases, by death. For example, murder, extortion and kidnapping are felonies; a minor fist fight is usually charged as a misdemeanor, and a speeding ticket is generally an infraction.