Last Thursday, Mexico’s National Human Rights Commission revealed that three young American siblings were executed by Mexican marines and a border mayor's paramilitary security team in 2014.

Erica Alvarado Salinas, 26, Alex Alvarado, 22, and Jose Angel Alvarado, 21, disappeared on October 13, 2014. They had been visiting their father in El Control, a small town near Matamoros, and had left to visit their mother’s home in Progreso, Texas.

On October 29, 2014, their bodies, along with Salinas’ boyfriend, Jose Guadalupe Castaneda Benitez, 32, who was from Mexico, were found in a field east of Matamoros, all of them shot in the head. Benitez had been convicted three times for illegal entry into the U.S. and was “possibly associated” with a criminal organization, according to a Homeland Security Investigations document; Erica Salinas and Alex Alvarado had been arrested on marijuana smuggling charges on October 7, 2013, at the Falfurrias checkpoint operated by U.S. Border Patrol.

The commission stated that several men who reported being arrested the same day the victims disappeared, said that the four victims were forced into a vehicle owned by the security detail of then-Matamoros Mayor Leticia Salazar Vázquez; the witnesses testified that they saw the victims taken to an empty lot to be beaten and interrogated by the marines. The commission asserted that Mexican state officials, marines, and state and federal police lied to cover up the killings.

The mother of the three siblings said in early November 2014 that a soldier at a military installation in Matamoros witnessed the siblings enter the barracks of a police unit called Grupo Hercules. Raquel Alvarado said, “He told us Erica was very beaten, and Jose Angel’s legs were injured. They hit her as though she were a man.”

Matamoros lies within the dangerous state of Tamaulipas. In January the U.S. State Department issued an advisory for Tamaulipas and four other Mexican states warning American citizens, "Do not travel due to crime. Violent crime, such as murder, armed robbery, carjacking, kidnapping, extortion, and sexual assault, is common."