Craig Juvenile Law Lawyer, Missouri

The privilege that allows the president and other high officials of the executive branch to keep certain communications private if disclosing those communications would disrupt the functions or decisionmaking processes of the executive branch. As demonstrated by the Watergate hearings, this privilege does not extend to information germane to a criminal investigation.

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.

An order signed by a judge that directs owners of private property to allow the police to enter and search for items named in the warrant. The judge won't issue the warrant unless she has been convinced that there is probable cause for the search -- that reliable evidence shows that it's more likely than not that a crime has occurred and that the items sought by the police are connected with it and will be found at the location named in the warrant. In limited situations the police may search without a warrant, but they cannot use what they find at trial if the defense can show that there was no probable cause for the search.

A rule of evidence that disallows the use of illegally obtained evidence in criminal trials. For example, the exclusionary rule would prevent a prosecutor from introducing at trial evidence seized during an illegal search.

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.

An affirmative defense to a crime. Self-defense is the use of reasonable force to protect oneself from an aggressor. Self-defense shields a person from criminal liability for the harm inflicted on the aggressor. For example, a robbery victim who takes the robber's weapon and uses it against the robber during a struggle won't be liable for assault and battery since he can show that his action was reasonably necessary to protect himself from imminent harm.

A prosecution for murder in which the jury is also asked to decide if the defendant is guilty and, if he is, whether he should be put to death. When a prosecutor brings a capital case (also called a death penalty case), she must charge one or more 'special circumstances' that the jury must find to be true in order to sentence the defendant to death. Each state (and the federal government) has its own list of special circumstances, but common ones include multiple murders, use of a bomb or a finding that the murder was especially heinous, atrocious or cruel.

The component parts of crimes. For example, 'Robbery' is defined as the taking and carrying away of property of another by force or fear with the intent to permanently deprive the owner of the property. Each of those four parts is an element that the prosecution must prove beyond a reasonable doubt.