Four of the 16 soldiers accused of the murder of six Jesuit priests and two maids at the Universidad Centroamericana (UCA) in El Salvador on Nov. 16, 1989, are now behind bars following police raids over the weekend.

The four men are Sgt. Zarpate Tomas de Castillo, Sgt. Ramiro Avalos Vargas, Lt. José Antonio Ramiro and Col. Guillermo Alfredo Benavides, former director of the military academy. The other 12 are still at large, and President Salvador Sanchez Ceren, a former guerrilla in the Farabundo Marti National Liberation Front (FMLN), has invited them to surrender.

A 17th suspect is the former Minister of Defense, Col. Inocente Montano, arrested and tried in the U.S. for immigration fraud and awaiting extradition to Spain to face charges in the massacre. Five of the slain Jesuits were Spaniards. A U.S. court approved the extradition Feb. 5.

In 2008, a human rights group filed a complaint in Spain, under the principle of universal jurisdiction, against 14 Salvadoran soldiers and Alfredo Cristiani, then president of the right-wing Nationalist Republican Alliance (ARENA) party. The following year, Spanish courts opened proceedings, and in 2011 a judge issued an Interpol red notice for the suspects’ arrest. Last month, the red notice was renewed, and Salvadoran authorities authorized the first round of raids this weekend. Now Spain will again seek their extradition, and it will be up to the Supreme Court of El Salvador to grant it or not.

In 2011, the country’s highest court held that the Interpol notice constituted “a search mechanism” and did not authorize capture, and in 2012 the court denied extradition. In 1991, the group implicated in the massacre was tried in El Salvador, but the amnesty granted by the 1992 accords that ended the country’s civil war spared them a conviction. Because of the amnesty, few have faced consequences for the rampant and gruesome war crimes that marked the 1980-1992 conflict that left 75,000 dead and 8,000 disappeared.

Among the “eight UCA martyrs,” as they’re remembered in El Salvador, were Ignacio Ellacuría, rector of the university. He was a liberation theologist and close to Archbishop Oscar Romero, who was also killed by a death squad at UCA on March 24, 1980. The massacre of the priests, the housekeeper and her 16-year-old daughter was the work of the Atlacatl Battalion, trained in North Carolina. The massacre caused an international sensation, which partly forced Cristiani to negotiate with FMLN to end the war.

Since then, the martyrs of UCA are memorialized in November, and Salvadorans renew demands for justice. But the country is far from coming to terms with its past, and many voices still come out in favor of the killers.

“We are interested above all that people know the truth,” José Maria Tojeira, director of campus ministry at UCA, told reporters. He noted other unpunished massacres, like the the one at El Mozote in 1981. In the village of El Mozote, the Atlacatl Battalion, under the command of Domingo Monterrosa, tortured and killed 1,200 men, women and children. A battalion officer at the time reportedly justified the indiscriminate slaughter of civilians saying, “All you sons of bitches are collaborators.”