In the United States, sentences to confinement for life are typically reserved for those crimes deemed by policymakers to be the most heinous. The issue has contributed to growing concern considering the significant increase in the number of incarcerated inmates and of life sentences imposed by the courts. Depending on the jurisdiction (e.g., state versus federal), the jury or judge is responsible for imposing sentences. Some jurisdictions distinguish between a life sentence without the possibility of parole, a natural life sentence, and a life sentence with the possibility of parole. Others do not. Those sentenced to life without the possibility of parole must serve the rest of their natural lives in prison.