What to Know The bodies of four young men, ages 16, 18 and 20, were found in a Long Island park Wednesday night

Police say they were killed with "extreme violence using sharp instruments" in a manner consistent with the MS-13 gang

Gang violence has been a problem in Central Islip, Brentwood and other Long Island communities for more than a decade

UPDATE: FBI Joins Probe Into Brutal Park Slayings



Four young men were found violently killed in a park in a Long Island neighborhood that has for years contended with a growing problem of gang violence, authorities said Thursday.

The victims were found in the Central Islip Recreation Village Park near Lowell Avenue and Clayton Street in Central Islip Wednesday night, authorities said. They appeared to have been killed with a sharp-edged instrument, in a manner consistent with the modus operandi of the violent MS-13 gang, Police Commissioner Timothy Sini said at a news conference.

The victims have been tentatively identified, but their names were not being released until definitive IDs have been made. One of the victims was 16 years old, two were 18 and the fourth victim was 20 years old.

The killings happened in recent days, and all the young men suffered "siginificant trauma" to their bodies, Sini said.

"We're going to do everything in our powers to solve these murders. We have all hands on deck, and we're working closely with the FBI," he said.

Authorities are offering a $25,000 cash reward for information in the case.

Members of the Guardian Angels, a citizens safety group, were patrolling the park Thursday night to help the rattled community feel at ease.

"We want everyone to be safe," Benjamin Garcia, a Guardian Angel, said. "Everyone should be able to go to the park, go to the movies, go to dinner without fearing the gangs will do something."

Parents and relatives of missing 16-year-old Justin Llivicura had gone to the park earlier in the day to talk with police officers and ask for more information on the bodies found there. The teen went to the park with friends on Tuesday but has not been answering his phone since then, relatives said. The family filed a missing person report with police on Wednesday.

"I'm looking for my son," said father Marcelo Llivicura. "I don't know if this is my son or no."

Sini declined to say at the news conference whether the family members of the possible victims have been notified, saying only that the media would be notified once official identifications have been made on the bodies.

The discovery of the bodies comes about a month after the arrest of eight MS-13 gang members in connection with the September killings of two teenage girls in nearby Brentwood.

Gang violence has been a problem in Central Islip, Brentwood and other Long Island communities for more than a decade, but Suffolk County police and the FBI began pouring resources into a crackdown after the killings of the girls, along with two other Brentwood High School students involved in separate killings, sparked outrage. Brentwood and Central Islip are neighboring communities comprised of large populations of working class Hispanic and other minorities, located about 2.5 miles apart.

Prosecutors said Kayla Cuevas, 16, was targeted last summer by a group of four gang members, including two juveniles, because she had been feuding with MS-13 members at school and on social media. The posse, which had been roving in a car looking for gang enemies, attacked when they came across her walking with Nisa Mickens, 15, in the street. The inseparable best friends were attacked with a machete and baseball bats, officials said.

Nisa "was simply at the wrong place at the wrong time, hanging out with her childhood friend," former U.S. Attorney Robert Capers said in announcing the arrests. The site where the bodies were found is just blocks away from the federal courthouse where the alleged killers are being prosecuted.

The MS-13 gang, also called Mara Salvatrucha, is believed to have been founded as a neighborhood street gang in Los Angeles in the mid-1980s by immigrants fleeing a civil war in El Salvador. It grew after some members were deported to El Salvador, helping to turn that country into one of the most violent places in the world. It's now a major international criminal enterprise with tens of thousands of members in several Central American countries and many U.S. states.

Sini said Thursday, "This is certainly a reminder of how violent they are, that they're still here."

"This is a long-term war," he said, invoking his past declarations of going to battle against the violent gang in Suffolk. "We maintain our resolve, we will solve these murders and we will continue to fight."

Last December, President Donald Trump referenced the slayings in Brentwood during a profile for his Time magazine Person of the Year award.

One of the Republican president's priorities is a crackdown on immigrants who are in the country illegally and have committed crimes. He promised as much in a Time interview, referencing a Newsday story about the killings.

"They come from Central America. They're tougher than any people you've ever met," he said. "They're killing and raping everybody out there. They're illegal. And they are finished."