The authorities have still not identified the man suspected of killing an Oregon State Penitentiary inmate.
Homicide detectives have been investigating the death of 45-year-old Joseph Akins, a convicted murderer who was found dead Saturday at the Salem prison.
Officials said a suspect was being held in segregation at the prison. The name was withheld on instructions from the Marion County district attorney.
The Statesman Journal newspaper reports that whoever is charged could end up on death row.
Four of the 37 inmates on death row are there because their aggravated murder convictions involve the killing of an inmate.
That includes Gary Haugen, whose much-publicized request to die was blocked by Gov. John Kitzhaber and the Oregon Supreme Court.