Greig Criminal Lawyer, New York

A seldom-used test for criminal insanity that labels the person insane if he could not control his actions when committing the crime, even though he knew his actions were wrong.

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).

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.

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).

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.

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.

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.