Gilgo Beach Serial Killer Suspect Rex Heuermann Looks Stone-Cold in First Court Appearance

Rex Heuermann, the man suspected of being the Long Island Serial Killer, appeared in court for the first time, RadarOnline.com has learned.

Heuermann, a Manhattan-based architect and longtime Massapequa Park resident, was arrested on July 13 in connection to the Gilgo Beach murders.

On Tuesday, the 59-year-old appeared before a judge in a Suffolk County courtroom to face 6 counts of murder: three first-degree murder charges and three second-degree murder charges.

Towering above bailiffs at 6-foot 5-inches, Heuermann entered court in handcuffs, a black blazer, and a blue button-down.

Heuermann remained stoic as he was read his charges related to the 2009 murder of sex worker Melissa Barthelemy, as well as the 2010 murders of Megan Waterman and Amber Lynn Costello, both escorts.

The architect pleaded not guilty to all 6 murder charges.

While he has not yet been charged, Heuermann remains the prime suspect for a fourth murder, Maureen Brainard-Barne, who was killed in 2007.

Heuermann's court appearance was a long time coming since the 2010 disappearance of Shannan Gilbert, a local sex worker, created a domino effect of gruesome discoveries for Suffolk County police.

While searching for Gilbert, officers discovered the discarded remains of 11 bodies, including a toddler, along Gilgo Beach. The bodies were found wrapped in a distinctive burlap fabric.

Thirteen years passed without answers for the victim's families until police announced a break in the case that they believed connected Heuermann to the brutal slayings.

Law enforcement revealed that while surveilling Heuermann, the suspect threw away a pizza crust. What began as Heuermann's trash ended as investigators' treasure after a DNA sample from the crust was positively linked to crime scene evidence.

Additionally, investigators claimed cell phone data linked Heuermann to crimes.

According to Fox 5 NY, arrest records showed that Heuermann was accused of using burner phones to contact victims' families after their disappearance.

In one instance, Heuermann allegedly used one victim's phone to contact her loved ones — and reportedly admitted to sexually assaulting and killing her during the call.

Heuermann landed on police's radar in 2022 after an old tip regarding a pickup truck connected to Costello's disappearance was linked to the father of two.