Steinauer Juvenile Law Lawyer, Nebraska

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.

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 party's job of convincing the decisionmaker in a trial that the party's version of the facts is true. In a civil trial, it means that the plaintiff must convince the judge or jury 'by a preponderance of the evidence' that the plaintiff's version is true -- that is, over 50% of the believable evidence is in the plaintiff's favor. In a criminal case, because a person's liberty is at stake, the government has a harder job, and must convince the judge or jury beyond a reasonable doubt that the defendant is guilty.

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.

Someone who helps another person (known as the principal) commit a crime. Unlike an accessory, an accomplice is usually present when the crime is committed. An accomplice is guilty of the same offense and usually receives the same sentence as the principal. For instance, the driver of the getaway car for a burglary is an accomplice and will be guilty of the burglary even though he may not have entered the building.

The money posted by a 'bondsman' for a defendant who cannot afford his bail. The defendant pays a certain portion, usually 10%. If the defendant fails to appear for a court hearing, the judge can issue a warrant for his arrest and threaten to 'forfeit,' or keep, the money if the defendant doesn't appear soon. Usually, the bondsman will look for the defendant and bring him back, forcefully if necessary, in order to avoid losing the bail money.

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.

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 branch of the United States government with power derived directly from the U.S. Constitution. Federal courts decide cases involving the U.S. Constitution, federal law--for example, patents, federal taxes, labor law and federal crimes, such as robbing a federally chartered bank--and cases where the parties are from different states and are involved in a dispute for $75,000 or more.