OMAHA, Neb. -- An inmate at RTC died while serving out his sentence.

Officials said 39-year-old Ryan Poe died on Friday at the Reception and Treatment Center. The cause of death has not been determined but Poe was reportedly being treated for a medical condition at this time.

According to court documents, Poe was convicted of first-degree murder in Douglas County. His life sentence started on July 12, 2006.

As is the case whenever an inmate dies in the custody of the Nebraska Department of Correctional Services (NDCS), a grand jury will conduct an investigation.