When the criminals found out that the man was not carrying the expected large amount of cash, they kidnapped him.
The man was identified at the time as Mark Lester Metz. Agents now say he is 36.
Metz was abducted in his own car early one November morning in the parking lot of a casino near Juan Santamaría airport in Alajuela.
Eventually the crooks had him pull over, at which point they stabbed him at least three times in the chest, locked him in the trunk of his car and set the vehicle on fire.
Firefighters were called to the scene quickly enough to rescue Metz, but he still went to the hospital with much of his body burned, attendants said.
Monday judicial investigators detained three persons, a Colombian, his girlfriend and another Costa Rican male. The arrests came at three locations. The Colombian, who is 30, was detained in Pavas. The 40-year-old girlfriend was detained in Coyol de Alajuela. The second man, who is 43, was detained in la Garita de Alajuela.
Agents said that the assailants were under the impression that Metz was carrying a sum of money. When they found he did not have the cash, they carried him off.
It still is unclear if Metz was able to free himself from the
vehicle trunk or if fire fighters did so when they arrived.
The suspects are facing allegations of attempted murder.