The act of releasing someone from custody or confinement; legally can mean release after arrest/detention, including acquittal or discharge.
誤認逮捕だったため、被疑者はすぐに釈放された。
Because it was a mistaken arrest, the suspect was released immediately.
保釈金が支払われ、容疑者は釈放された。
Bail was posted and the suspect was released.
裁判で無罪になり、ついに釈放されたと報じられた。
It was reported that he was finally released after being found not guilty at trial.