Suspected Gilgo Beach Killer Rex Heuermann to Be Indicted on New Charge

Rex Heuermann -- the suspected Gilgo Beach serial killer -- will be hit with a new charge tied to his murder case ... TMZ has confirmed

Sources with direct knowledge tell us Heuermann will be arraigned in Riverhead, NY on Thursday -- and while the exact details aren't official yet ... we're told he's expected to be hit with yet another murder charge ... his fifth in the sweeping case.

Suffolk County District Attorney Raymond Tierney told CBS News Monday ... "There were a number of necessary investigative steps that were taken, we've pointed out just some of them. Thursday, you will see the fruits of that investigation." The identity of the new alleged victim has yet to be released.

The update comes 2 weeks after police once again searched Heuermann's Massapequa Park home ... setting up a command center in the picturesque Long Island neighborhood.

Heuermann has already been accused of killing Amber Lynn Costello, Melissa Barthelemy, Megan Waterman and Maureen Brainard-Barnes over a decade ago ... with prosecutors pointing to DNA evidence and phone records to link him to the crimes. He was arrested last July for the killings of Amber, Melissa and Megan -- later charged with the death of Maureen in early 2024.

He has pled not guilty to all of the charges.

Remember, authorities say they found human remains belonging to 11 different people in the area between 1996 and 2011. Heuermann's alleged victims -- sex workers who found their clients through Craigslist and other sites -- were discovered in shallow graves in Gilgo Beach in 2010.

Their deaths remained a mystery for over 10 years ... that is until Heuermann became a suspect after police reopened the investigation in 2022.