The Gilgo Beach killings suspect is charged with two more murders. Here's what to know

The man accused of killing multiple women and dumping their remains on a Long Island, N.Y., beach has been charged with two more murders.

Rex Heuermann, a 60-year-old architect, appeared in court Thursday for his arraignment in the deaths of Jessica Taylor and Sandra Costilla, two young women who police believe were the victims of men targeting sex workers.

Heuermann has already been charged in the murders of four other women, known as the “Gilgo Four,” whose remains were found within the same quarter-mile stretch on Gilgo Beach in 2010.

It’s been almost a year since his arrest marked a breakthrough in a decade-long investigation into a series of disappearances that grabbed national attention and inspired the 2020 Netflix film Lost Girls.

Heuermann has pleaded not guilty to all murder charges. He was ordered to be held behind bars without bail and is due to return to court on July 30.

Here’s what else to know about the case.

The suspect has been charged with murdering six women

Between 2010 and 2011, police uncovered the remains of 11 people found near Gilgo Beach between Nassau and Suffolk counties on Long Island. Most of them were sex workers who were killed as early as 1996, according to Suffolk County Police. Investigators have long suspected a serial killer was responsible, but have also said that the victims were unlikely murdered by the same killer.

The dead include Jessica Taylor, Valerie Mack, Shannan Gilbert, Amber Lynn Costello, Megan Waterman, Melissa Barthelemy and Maureen Brainard-Barnes, all in their 20s.

Police said they were unable to determine the cause of death for Gilbert — whose disappearance led to the discovery of the string of slayings — but said her death was likely accidental, a conclusion her family disputed.

In July 2023, a major break in the case came with the arrest of Heuermann.

He was then charged in the killings of three of the so-called Gilgo Four women: Barthelemy, 24, Waterman, 22, and Costello, 27. He was charged with killing the fourth, Brainard-Barnes, this January.

Cell phone location data and DNA samples found on the remains initially tied him to the four women.

Since his arrest, several pieces of evidence have pointed to Heuermann as the suspect.

He lived in Massapequa Park, where a few of the victims were last seen.

A witness described seeing a victim, Costello, driven by a man in a Chevrolet Avalanche. It was later discovered that Heuermann owned a Chevrolet Avalanche.

Subpoenas and search warrants linked Heuermann to multiple burner cellphones used to contact victims. An email associated with Heuermann's suspected burner cellphones was repeatedly used to conduct "thousands of searches" related to "sex workers, sadistic, torture-related pornography and child pornography," according to court records.

New charges suggest the serial killings began earlier than previously thought

The new murder charge against Heuermann for the 1993 death of Costilla makes her the earliest known victim in the string of murders and suggests the architect allegedly began killing 30 years ago — earlier than police previously thought.

In November 1993, the remains of Costilla, 28, were found by hunters in a wooded area of Southampton, N.Y., according to a recent court filing.

Taylor, another victim, disappeared in July 2003. Her remains were discovered that year and in 2011, in two separate locations. In 2003, a dog walker found her body decapitated and arms severed in a wooded area of Manorville, about 40 miles from Heuermann’s home. In 2011, her skull, hands and forearm were recovered less than a mile from where the Gilgo Four were found.

In both cases, male hairs found on the remains of both Costilla and Taylor were tested and found to be a likely DNA match to Heuermann, prosecutors said.

The suspect allegedly kept a planning document to “blueprint” his killings

The recovery of data on hard drives and other devices revealed that Heuermann had a “significant collection of violent, bondage, and torture pornography" dating back to 1994, according to court documents filed this week.

The collection depicts “pornographic images that are consistent with the crime scenes of both Sandra Costilla and Jessica Taylor,” Suffolk County District Attorney Raymond Tierney said at a press briefing on Thursday.

Prosecutors also announced the recent discovery of a suspected planning document Heuermann used to “methodically blueprint” his killings. The Microsoft Word document, which Heuermann allegedly tried to delete, was recovered in March on a hard drive found in the architect’s basement. It was one of more than 350 devices investigators retrieved during searches of his home.

The document, pictured in the court filing, includes checklists that appear to involve steps to complete before, during and after killings, according to the court documents.

The tasks are littered with references to sexual and mutilation acts done to victims, prosecutors said.

The steps include reminders to “have story set” and to destroy pictures and other apparent evidence. A “body prep” list has a note to “remove head and hands."

If convicted on the current charges, Heuermann faces multiple sentences of life without parole.

NPR's Juliana Kim contributed to this report.