Prosecutors say the man accused of the Gilgo Beach serial murders kept a crime “plan” on his computer

Riverhead, New York — A New York architect accused of murdering multiple women and leaving their bodies strewn along the Long Island coast kept a “blueprint” of his crimes on his computer, prosecutors revealed Thursday as they charged Rex Heuermann with two more murders.

Heuermann, 60, appeared before a judge to face charges in connection with the deaths of Jessica Taylor and Sandra Costilla, two young women long suspected of being victims of men who preyed on prostitutes. He was previously accused of murdering four other women in a series of murders known as the Gilgo Beach serial murders.

Taylor disappeared in 2003. Costilla was murdered 30 years ago, in 1993, and her inclusion in the case indicates that prosecutors now believe Heuermann has been killing women for much longer than previously thought.

The new charges follow recent police searches of Heuermann’s Massapequa Park home and a wooded area on Long Island in connection with the investigation.

In the lawsuit, prosecutors said they were able to use new forensic testing methods to match hair found on or near both victims’ bodies to a DNA profile that likely matched Heuermann. Additionally, prosecutors say they recovered a file on a hard drive in his basement containing a “methodical plan” for his murders.

The all-caps document contains a series of checklists with tasks to complete before, during and after the killings, as well as practical lessons for “next time.” “get some sleep before the hunt” and “set the story.”

One section, titled “Things to Remember,” appears to highlight lessons learned from previous killings, prosecutors say, such as using heavier ropes and limiting noise to maximize “play time.” The “body preparation” checklist includes, among other things, a note to “remove the head and hands.”

Prosecutors believe the post may link Heuermann to another victim, Valerie Mack, whose partial skeletal remains were discovered near Taylor’s body after her 2000 disappearance.

Heuermann has not been charged in Mack’s death. But asked during a news conference after Thursday’s hearing whether he was a suspect, District Attorney Ray Tierney replied: “That’s safe to say.”

Heuermann pleaded not guilty to killing Taylor and Costilla at trial and was ordered held without bail. His lawyer Michael Brown said outside court that Heuermann “clearly is in a bad position with the new charges.”

Tierney then said the additional charges provide a “small measure of closure” for the victims’ families.

Since late 2010, police have been investigating the deaths of at least 10 people – mostly women sex workers – whose remains were discovered off an isolated highway near Gilgo Beach on Long Island’s south shore.

These victims disappeared over a period of at least 14 years. Exasperated detectives merely halted progress in identifying potential suspects. Investigators have long said it is likely that not all of the deaths were the work of the same killer. Some of the victims disappeared in the mid-1990s. Investigators concluded that an eleventh person who disappeared in 2010 from the barrier island community of Oak Beach drowned accidentally.

Heuermann, who lived across the bay where the bodies were found, was arrested last July. Prosecutors say the new investigative task force used cellphone location data and DNA samples to link the architect to some of the victims. He was accused of killing four women: Megan Waterman, Melissa Barthelemy, Amber Lynn Costello and Maureen Brainard-Barnes.

Investigators, who thoroughly searched Heuermann’s home and excavated his yard last summer, returned to the house last month and searched it again for almost a week. According to Heuermann’s wife’s lawyer, they focused their efforts mainly in the basement.

It followed an April search for a wooded area in Manorville, about 65 kilometers east of Heuermann’s home, and in the North Sea village of Southampton, where Costilla’s remains were discovered decades ago.

Tierney said the planning document was found in March, prompting the recent search.

Prosecutors also said they found in Heuermann’s possession a book by retired FBI agent John Douglas, “The Cases That Haunt Us.” They say the planning document referenced specific pages from another of Douglas’s works, “Mind Hunter,” that allude to the personality types of serial killers and profiles of people who use mutilation and sexual violence.

Jessica Taylor, 20, disappeared in 2003 while working as an escort in New York. Some of her remains were discovered in Manorville the same year. Other remains were found during a 2011 search of beach brush on Ocean Parkway, the road where other Gilgo Beach victims were found.

Taylor’s mother, Elizabeth Baczkiel, was in court for Thursday’s hearing. She showed photos of her daughter from childhood, but did not talk to reporters. Her lawyer, Gloria Allred, read Beczkiel’s statement in which she described her daughter as “loving, compassionate and incredibly funny” and said she would be a great mother.

“My dear daughter, you will never be forgotten,” the statement said. “You will remain in our hearts forever.”

Valerie Mack, 24, who worked as an escort in Philadelphia, disappeared in 2000 and was last seen by her family in Port Republic, New Jersey, near Atlantic City. Some of her skeletal remains were discovered that same year in Manorville Forest. More of her remains were found in 2011 during searches around Gilgo Beach.

Mack’s remains, initially known as “Jane Doe No. 6,” remained unidentified until 2020, when genetic testing revealed her identity.

Costilla was 28 when she was murdered and lived in New York.

A decade ago, Suffolk County prosecutors said publicly that they believed Costilla was murdered by John Bittrolff, a local carpenter convicted of murdering two other women whose bodies were found in the same part of Long Island.

But Bittrolff was never charged with Costilla’s death due to lack of evidence. He insists he didn’t kill anyone, and his lawyers didn’t immediately respond to phone messages and emails seeking comment Thursday.