Trump, Visiting Epicenter of MS-13 Killings, Demands Tougher Immigration Laws

He has appeared at times to suggest that the vast majority of immigrants flowing into the United States from Mexico are members of the brutal gang. In fact, of the tens of thousands of people apprehended at the border in the fiscal year that ended in September, only 228 were members of MS-13, down from 437 in 2014, according to Customs and Border Protection.

The president has also linked the migration of young people fleeing Central America with gang members who exploit “loopholes” in the law to gain residency. These loopholes, according to immigrant advocates, are, in fact, legal protections for children escaping gang violence or family abuse.

On the dais, Mr. Mickens and his wife, Elizabeth Alvarado, were joined by Evelyn Rodriguez and Freddy Cuevas, the parents of Kayla Cuevas. All four had also attended the State of the Union address in January and have spoken out ever since their children were killed in September 2016. Ms. Alvarado wore a black T-shirt with her daughter’s picture on the front and “Justice for Nisa” on the back.

In the audience, the families of three of the four young men killed by MS-13 behind a soccer field in Central Islip in April 2017 sat wiping their eyes.

Lourdes Banegas, whose son, Michael Lopez, was killed in the April attack, said before Mr. Trump’s remarks that she supported the president’s efforts to go after MS-13. But she said his anti-immigrant language can be difficult to hear.

“Those that killed my son are animals. That’s true,” Ms. Banegas said. “They deserve to be deported. But since they are Latinos, and we are all also Latinos, they clump us all in together. That’s the problem.”

Carlos Lopez, Michael’s father, said he agreed with Mr. Trump’s call for a crackdown on the gang. Otherwise, he said, “there is going to be dead body, after dead body, after dead body, the way they found my son.”