BRETNWOOD, Long Island (WABC) -- For the fifth time since September, police have discovered the remains of a teenager in Brentwood, a community plagued by gang violence.The body of Jose Pena-Hernandez, 18, of Brentwood, was found Monday in a wooded area at Pilgrim Psychiatric Center.An autopsy will be conducted to determine the cause of death, but police said the case was being investigated as a homicide.Hernandez, who police say was a known gang member, was reported missing in June. Suffolk County police believe he was beaten to death."We didn't find those remains by accident," said Suffolk County Police Commissioner Timothy Sini. "We are putting an enormous amount of pressure on the criminal element in the Brentwood area."The heat, police say, has led to the arrests of 25 known gang members on a wide range of charges since Sept. 13th. But five of them face federal charges, which carry much longer sentences."They have a choice to make. They either are going to spend their adult lives in prison, perhaps their entire life in prison, or they're going to cooperate with law enforcement." said Sini.Oscar Acosta, who had been missing since May, and Miguel Garcia- Moran, who had been missing since February, were not members of the gang. Their remains were found last month.Suffolk County Police confirmed all three of the murders are related.Four Brentwood High School teens were killed or found dead within the past six weeks, all suspected victims of gang violence.Investigators began discovering the corpses on Sept. 13, when the badly beaten body of Nisa Mickens was found on a tree-lined street in Brentwood, a day before her 16th birthday. A day later, the beaten body of her lifelong friend, 16-year-old Kayla Cuevas, was discovered in the wooded backyard of a nearby home.The teenagers had been inseparable and shared an interest in basketball.Days later, police discovered the skeletal remains of Acosta, 19, and Garcia-Moran, 15, in a remote industrial area of the town.While investigators say the murders of Mickens and Cuevas are gang-related, they are not linked to the latest arrests."Two girls brutally murdered on the streets of Brentwood, we have three missing boys who we know were victims of murder, we have the additional murder of Mr. Stacks," said Sini. "We have a lot of cases that we need to get to the bottom of, and we will."A man identified as Dewann A.S. Stacks of Brentwood was found severely injured in the middle of a road in Brentwood last week and died at the scene.In the wake of the deaths, school administrators warned students not to wear clothing that risked offending vicious street gangs.There have been no arrests.