In late November 2018, Carla Stefaniak — an American tourist of Venezuelan descent — traveled to Costa Rica to celebrate her birthday and stayed at a vacation rental (Airbnb) in San Antonio de Escazú. She was reported missing a few days later. Her body was found buried and wrapped in plastic a short distance from the property, under circumstances suggesting more than one person was involved.
The initial theory from Costa Rica's Public Prosecutor's Office pointed to a lone robbery carried out by the property's security guard. The defense for the accused repeatedly argued that the crime scene had been contaminated, seeking to exclude the forensic evidence gathered by Costa Rican authorities.
From the early stages, Rivera Cheves maintained a different procedural theory: that between 5 and 7 people connected to the property were involved in the attack and the subsequent concealment of the body — not a single perpetrator. Given the victim's U.S. citizenship, the firm coordinated and facilitated the involvement of FBI agents from the United States in the forensic proceedings carried out in Costa Rica in 2018. This cross-border cooperation made it possible to run advanced biological analysis in the room where the attack occurred, ensuring the scientific evidence would withstand the defense's contamination objections.