Habeas corpus is a Latin term meaning "you have the body". It is a writ (court order) which directs the law enforcement officials who have custody of a prisoner to appear in court with the prisoner...
It is explicitly stated in the U.S. Constitution under Article I, Section 9.
Innocent until proven guilty.
A "Writ of Habeus Corpus" is presented to the court having jurisdiction in the circuit where the detainee is incarcerated.
The Framers of the Constitution of the United States.