A fugitive (or runaway) is a person who is fleeing from custody, whether it be from jail, a government arrest, government or non-government questioning, vigilante violence, or outraged private individuals. A fugitive from justice, also known as a wanted person, can be a person who is either convicted or accused of a crime and hiding from law enforcement in the state or taking refuge in a different country in order to avoid arrest.
Interpol is the international authority for the pursuit of trans-border fugitives. Europol is the European authority for the pursuit of fugitives who are on the run within Europe, and coordinates their search, while national authorities in the probable country of their stay coordinate their arrest. In the United States, the U.S. Marshals Service is the primary law enforcement agency that tracks down federal fugitives, though the Federal Bureau of Investigation also tracks fugitives.
As a verbal metaphor and psychological concept, one might also be described as a "fugitive from oneself". Finally, the literary sense of "fugitive" includes the meaning of simply "fleeing".
In many jurisdictions, a fugitive who flees custody while a trial is underway loses the right to appeal any convictions or sentences imposed on him, since the act of fleeing is deemed to flout the court's authority. Recently, convicted rapist Andrew Luster had his appeals denied on the basis that he spent six months as a fugitive (he was convicted in absentia).