A La Reforma prisoner has died from wounds inflicted in the institution.
The Ministerio de Justicia y Paz, which supervises the prison system, identified the dead man as Luis Angulo Palomino, 33.
He was convicted of murder and robbery.
A dispute appears to have grown out of a robbery of some 5,000 colons, a bit less than $10.
The suspect is another convicted murderer identified by the last name of López , said the ministry.
Angulo suffered a wound to the stomach and died in the Alajuela prison clinic, said officials.