Maria Webster, Melissa Rodriguez, and Marion Wanda Ayala, all of...

Maria Webster, Melissa Rodriguez, and Marion Wanda Ayala, all of Brentwood, stand at the memorial in memory of Brentwood High School students Nisa Mickens and Kyla Cuevas, who were mudered earlier this week, Saturday, Sept. 17, 2016. Credit: Steve Pfost

After the indictment of 13 MS-13 gang members yesterday, FBI Assistant Director-in-Charge William F. Sweeney Jr. said, “Whether you live in Brentwood or the Hamptons, you have a right to safety and security in your neighborhood.”

That’s the right promise.

The 41-count indictment has led to 11 arrests so far in seven deaths. The focus on gang violence in Brentwood tightened with the killings of Kayla Cuevas, 16, and Nisa Mickens, 15, in September, allegedly by gang members with baseball bats and machetes. Jose-Pena Hernandez, 18, was found fatally stabbed the next month. The four other killings occurred between 2013 and 2015.

The intense investigation that has followed has led to the arrests of 125 MS-13 members, and a 45 percent reduction in violent crime in Brentwood, according to Suffolk County Police Commissioner Tim Sini.

The killings of Cuevas and Mickens attracted the attention in November of President-elect Donald Trump as evidence for his immigration narrative, and fairly so. Authorities say 10 of the 13 people charged were in the United States illegally. Violent criminals here illegally cannot be allowed to have more victims, who are most often members of their own communities. Suffolk’s four-year withdrawal from a federal gangs task force in 2012 was a disastrous error. The gang structure in Brentwood has to be destroyed. Law enforcement is in Brentwood today and, as promised, it should not go away.— The editorial board