Suffolk County District Attorney Raymond Tierney is slated to announce what is tipped to be a “significant development” in the investigation into the Gilgo Beach killings in a press conference on Tuesday morning, according to a press release from his office.
The briefing – joined by members of the Gilgo Beach Homicide Investigation Task Force, Suffolk County Sheriff Errol Toulon Jr, and Acting Suffolk County Police Commissioner Robert Waring – will take place after Mr Heuermann appears for a court hearing at 9.30am ET at the Suffolk County Courthouse in Riverhead on Long Island.
In the court appearance, new charges are expected to be unsealed against Mr Heuermann, sources told NBC News and CBS News.
The accused killer is already charged with the murders of three women – Megan Waterman, Melissa Barthelemy and Amber Costello.
Now, he is expected to be hit with charges over the murder of a fourth woman.
It is not clear which victim the Manhattan architect could be accused of killing, as the remains of 11 victims were recovered from the Gilgo Beach area.
However, Mr Heuermann was previously named the prime suspect in the murder of Maureen Brainard-Barnes.
Brainard-Barnes, Waterman, Barthelemy and Costello are together known as the “Gilgo Four”.
All four were working as sex workers and disappeared after going to meet a client.
Their bodies were each found in December 2010 within one-quarter mile of each other, bound by belts or tape and some wrapped in burlap – all dumped along Gilgo Beach.
In total, the remains of 11 victims were found along the shores of Long Island in 2010 and 2011, sparking fears of one or more serial killers.
The horror discovery began back in May 2010 when Shannan Gilbert, a young woman also working as a sex worker, vanished after leaving a client’s house on foot near Gilgo Beach. She called 911 for help saying she feared for her life and was never seen alive again.
During a search for Gilbert in dense thicket close to the beach, police discovered human remains.
Within days, four victims – that of the “Gilgo Four” – had been found.
By spring 2011, the number of victims rose to 10.
Gilbert’s body was then found in December 2011.
Her cause of death is widely contested with authorities long claiming that it is not connected to the serial killer or killers but that she died from accidental drowning as she fled from the client’s home.
However, an independent autopsy commissioned by her family ruled that she died by strangulation and her family continue to believe she was murdered.
So far, no charges have been brought in connection to the other victims also found along the shores.
The case went unsolved for more than a decade before Mr Heuermann, a 60-year-old married father-of-two from nearby Massapequa Park, was suddenly taken into custody in July.
Court records show that Mr Heuermann was linked to the murders through a tip about his pickup truck, a stash of burner phones, “sadistic” online searches and phone calls taunting victims’ families.
His DNA was also found on one of the victims, while his wife’s hair was found on three of the four women he is connected to, according to prosecutors.
Following his arrest, investigators across the country began probing cold case murders for any potential ties to the accused killer, as it emerged he had links to the likes of Las Vegas.
Mr Heuermann has pleaded not guilty to the charges.