Costa Rican authorities on Sept. 12 said they had arrested four people in connection with the June killing of a retired Nicaraguan military officer and vocal critic of President Daniel Ortega.

Roberto Samcam, 67, was shot dead on the morning of June 19 after a man entered his condominium complex in the northeast of San José and fired multiple times with a 9mm pistol, Costa Rica’s Judicial Investigations Agency (OIJ) said. The gunman fled the scene.

OIJ Director Randall Zúñiga said agents carried out three raids on the north side of San José that led to the capture of three suspects, and a fourth person was arrested Thursday in the city of Cañas in the northwestern Guanacaste province. Authorities described one detainee as an intermediary who organized the operation, another as the alleged 20-year-old gunman and a third as the driver. The intermediary’s girlfriend was also taken into custody.

Zúñiga said investigators had not yet determined who ordered the killing or whether anyone outside Costa Rica was involved. He noted similarities between Samcam’s slaying and a 2024 attempted homicide of another Nicaraguan opposition figure, Joao Salgado, in which the assailants used a driver from the same neighborhood and the attacks were carried out in what he described as a “clumsy way.” Salgado survived that attack and accused a cell of Nicaragua’s Sandinista National Liberation Front of responsibility.

Samcam, a retired major, had lived in exile in Costa Rica since July 2018 after paramilitaries assaulted his home in Nicaragua amid a government crackdown on protests. He served as an expert witness for the Court of Conscience organized by Costa Rica’s Arias Foundation for Peace and Human Progress in 2020 to document alleged torture and abuses by the Nicaraguan government. Samcam published a 2022 book, Ortega: El calvario de Nicaragua, and a subsequent work criticizing President Ortega’s consolidation of power.

Since Nicaragua’s 2018 crackdown on widespread protests, hundreds of thousands of Nicaraguans have sought refuge in Costa Rica, and the Nicaraguan government has closed nongovernmental organizations and pursued opposition figures and religious groups, including the Catholic Church. Those developments have produced a wave of political exiles and a string of attacks and threats against critics living abroad, Costa Rican authorities and human rights groups say.

Costa Rican investigators said forensic and ballistic analyses are ongoing as they seek to build a case against the four detainees and identify any additional suspects. Zúñiga did not disclose the suspects’ nationalities or whether the arrests were expected to lead to charges; he said authorities would present findings to prosecutors as the inquiry continues.

The arrests mark the latest development in a broader investigation into violence targeting Nicaraguan dissidents in exile. Costa Rican officials have in past cases coordinated with foreign partners to probe alleged transnational operations, but Zúñiga emphasized that, as of Friday, investigators had not confirmed foreign direction or involvement in Samcam’s killing.

Prosecutors in Costa Rica will determine whether to press criminal charges. The OIJ said it would share its findings with families of victims and with relevant international bodies as required by law, while continuing efforts to identify any further suspects and the motives behind the attack.