Four suspected MS-13 gang members have been arrested in connection with the deaths of four teenagers, who were found butchered in a Long Island park in April.

According to federal court documents that were unsealed this week, Alexis Hernandez, Santos Leonel Ortiz-Flores and Omar Antonio Villalta, along with an unnamed juvenile, have been charged with the murders of Michael Lopez Banegas, 20, his cousin Jefferson Villalobos, 18, Justin Llivicura, 16, and Jorge Tigre, 18.

All four victims were found in Recreation Village Town Park in Central Islip on April 11th, and their bodies appeared to have been beaten to death and mutilated with machetes; at the time, Suffolk Police Commissioner Timothy Sini told reporters, "the manner in which they were killed is consistent with the modus operandi of MS-13." The killings prompted Governor Cuomo to create a "High Intensity Gang Unit" to aid Suffolk County police in combating MS-13.

The NY Times reports that two of the victims had come to the U.S. in order to escape gang violence in their native Honduras.

Yesterday, the three named defendants pleaded not guilty to murder charges in federal court in Central Islip. Authorities are reportedly investigating whether more alleged gang members may have been involved.

The arrests are eliciting mixed reactions among the victims' relatives, some of whom see them as a small step out of the darkness of loss. "I demand justice, what can I say," Bertha Ullaguari, Tigre's mother, told the Associated Press. "I want them to be tortured like my son was tortured."

Others say the arrests are bringing the pain back to the surface. "It’s like opening a wound again,” Marcelo Llivicura, the father of Justin, told the Times. "There’s nothing we can do, my son is gone. Still, there is the promise of justice. "I hope that they pay their debts," Llivicura added. They took the lives of these young boys just at the beginning of their own lives."

A spokesperson for the U.S. attorney for the Eastern District of New York declined Gothamist's request for comment.