La Penca bombing

On May 30, 1984, a bomb exploded during a press conference at La Penca, a remote outpost on the Nicaraguan side of the border with Costa Rica along the San Juan River. The press conference had been convened by Edén Pastora, a former Sandinista military commander who had switched allegiance to lead a Contra guerrilla group fighting the Sandinista government. Pastora was the presumed target and survived, sustaining severe leg injuries requiring skin grafts, but seven other people were killed, including American journalist Linda Frazier, Costa Rican cameraman Jorge Quirós, his assistant Evelio Sequeira, and four of Pastora's men. About a dozen others were seriously wounded.

The bomb was reportedly hidden in an aluminum camera case carried by a man posing as a Danish photographer named "Per Anker Hansen," who left the room shortly before the explosion and is believed to have detonated the device remotely using a walkie-talkie. "Hansen" was unhurt and disappeared afterward.

American journalist Tony Avirgan, who was injured in the bombing, and his wife Martha Honey investigated the attack and concluded the CIA was responsible. In 1986 the Christic Institute filed a $24-million lawsuit on their behalf against several individuals associated with Oliver North, including Rob Owen, John Hull, Richard Secord, Albert Hakim, and Thomas Clines; the case was dismissed in June 1988, with the Christic Institute ordered to pay roughly $1 million in costs to the defendants. In 1990, a Costa Rican examining magistrate accused the CIA of orchestrating the bombing through two intermediaries, and murder charges were laid against Felipe Vidal, described as a Cuban-American CIA asset, and John Hull, an American farmer living in Costa Rica.

In 1993, journalistic investigation—led by Miami Herald reporter Juan Tamayo and freelance journalist Doug Vaughn—identified the bomber as Vital Roberto Gaguine, an Argentine former member of the People's Revolutionary Army (ERP), through fingerprint matching and photo identification by Gaguine's family. Gaguine had died in 1989 during a guerrilla attack on the La Tablada barracks in Argentina.

In 2009, Swedish journalist and La Penca survivor Peter Torbiörnsson disclosed that Renán Montero, a Cuban military counter-intelligence officer working with the Sandinista Ministry of the Interior, had asked him to escort "Hansen" to the press conference. Torbiörnsson submitted a declaration to Nicaraguan police accusing Montero, former Sandinista Minister of the Interior Tomás Borge, and former Nicaraguan state security chief Lenín Cerna of masterminding the bombing, but was unable to press charges successfully. In 2011, Torbiörnsson released the documentary Last Chapter, Goodbye Nicaragua, which included an interview with Luis Carrión, Borge's former deputy, stating he learned the bombing was an operation of the Ministry's intelligence directorate, and footage of Torbiörnsson confronting Borge directly.