A 43-year-old security ministry employee is presumed to have been abducted Monday night from Calle La Quesera in San Miguel de Naranjo.
About six hours later the suspected abductee was found dead alongside the Autopista Bernardo Soto.
The Ministerio de Seguridad Pública identified the dead man as Melsin Gerardo Carrillo Argüello.
The man worked as a radio operator for the ministry and had 22 years of service there. He had been beaten before he was killed, said agents.
Robbery was not a motive. Investigators said they found a bag nearby that contained 337,000 colons, about $640.
Agents had been on the case since 11 p.m. Monday when a 911 caller reported the abduction. A passerby found the body about 5:30 a.m.