Federal prisoners are individuals who have committed crimes that go against the laws of the entire country, not just a specific state. As a result, they are incarcerated in federal prisons rather than state prisons. Full definition
These changes reduced the sentences of, and is continuing to lead to the early release of, many thousands of federal prisoners. (sentencing.typepad.com)
It's the single largest federal prisoner release in American history. (relevantmagazine.com)
He is the only federal prisoner to ever receive a death sentence. (businessinsider.com)