A February affidavit from a Federal Bureau of Investigation special agent about the transnational gang MS-13 reveals a member was instructed to say he is “fleeing the violence in El Salvador” when dealing with police.

The FBI special agent details how Joel Martinez, aka “Animal,” was promoted to “homeboy” status in a Boston MS13 gang after stabbing 15-year-old Irvin De Paz to death in September 2015. According to the affidavit, rival 18th street gang members sought to kill Martinez and he had to flee. One MS-13 member, “told Martinez that when dealing with the police he should be humble and say that he is fleeing from the violence in El Salvador,” FBI special agent Jeffrey Wood wrote.

The Obama administration has expanded refugee opportunities for individuals and families in Central American countries, citing the violence currently in the region. In January 2016, Secretary of State John Kerry said, “I am pleased to announce that we have plans to expand the U.S. Refugee Admissions Program in order to help vulnerable families and individuals from El Salvador, Guatemala and Honduras.”

The United States is set to take in 85,000 refugees in 2016.

The affidavit goes on to detail the violent and international nature of MS-13. Wood wrote that the gang transformed into a transnational criminal organization after refugees fled to Los Angeles in the 1990s.

“MS-13’s primary functioning principles center on violence, including murder, and a strict military structure of communication and command, headquartered in El Salvador and spread throughout various ‘programs’ and ‘cliques’ in the United States,” Wood wrote.

“A portion of the dues from each clique are also provided, usually via wire transfer, to the incarcerated MS-13 leaders in El Salvador,” the affidavit continued. Wood wrote that it is difficult for law enforcement to detain MS-13 members as they “frequently leave the jurisdiction and take up residence with an MS-13 clique in another state or country.”

The gang is infamous for their violence towards suspected police cooperators. “Perhaps the most infamous historical example of MS-13’s brutality toward suspected cooperators is the case of Brenda Paz, a former MS-13 federal cooperator, who was brutally stabbed to death in 2003 by MS-13 gang members,” Wood wrote in the affidavit. Paz was four months pregnant.

There are over 6,000 members of MS-13 in the United States and over 30,000 internationally centered in the countries of Mexico, Honduras, Guatemala, and El Salvador, the affidavit states. The top countries of origin for illegal immigrants to the United States in 2015 were Mexico, Guatemala, Honduras, and El Salvador.

The affidavit states the gang recruits “at local high schools in cities with large immigrant populations from Central America.” In order to join the gang and become a “homeboy,” one has to kill a rival gang member.