Man charged in NY serial killings kept 'blueprint' of crimes, prosecutors say

A man stands by another man in a courtroom.

By PHILIP MARCELO

June 6, 2024 1:46 PM PT

RIVERHEAD, N.Y. — The New York architect accused of murdering multiple women and leaving their corpses scattered along the Long Island coast kept a “blueprint” of his crimes on his computer, prosecutors revealed Thursday as they brought charges against Rex Heuermann in two more killings.

Heuermann, 60, appeared before a judge to be arraigned in the deaths of Jessica Taylor and Sandra Costilla, two young women who were long suspected of being the victims of men preying on sex workers. He had previously been charged with murder in the slayings of four other women in a string of deaths known as the Gilgo Beach serial killings.

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

The new charges came after police searches of Heuermann’s Massapequa Park home and a wooded area on Long Island tied to the investigation.

In a court filing, prosecutors said they were able to use new forensic testing methods to match hairs found on or near the vicinity of both victims to a DNA profile that is a likely match to Heuermann. Additionally, prosecutors say they recovered a file on a hard drive in his basement used to “methodically blueprint” his killings.

The all-caps document features a series of checklists with tasks to complete before, during and after the killings, as well as practical lessons for “next time.” Among the dozens of entries written are reminders to clean the bodies and destroy evidence, to “get sleep before hunt” and to “have story set.”

One section, titled “things to remember,” appears to highlight lessons from previous killings, prosecutors said, such as using heavier rope and limiting noise in order to maximize “play time.” A “body prep” checklist includes, among other items, a note to “remove head and hands.”

Prosecutors believe that entry may connect Heuermann to yet another victim, Valerie Mack, whose partial skeletal remains were discovered near the body of Taylor after her disappearance in 2000.

Heuermann has not been charged in the death of Mack. But asked during a news conference after Thursday’s hearing if he was a suspect, Dist. Atty. Ray Tierney replied, “That’s fair to say.”

Tierney also acknowledged that the “blueprint” document, which Heuermann had attempted to delete, was a “significant impetus” for the renewed search across Long Island in recent weeks; it was recovered in March from the more than 350 electronic devices seized from the suspect’s home.

Heuermann pleaded not guilty to killing Taylor and Costilla during the hearing and was ordered held without bail. His lawyer, Michael Brown, said outside court that Heuermann is “obviously in a bad place in terms of the new charges.”

Afterward, Tierney said the additional charges provide “some small measure of closure” for the victims’ families.

Since late 2010, police have been investigating the deaths of at least 10 people — mostly female sex workers — whose remains were discovered along an isolated highway not far from Gilgo Beach on Long Island’s south shore.

Those victims disappeared over a span of at least 14 years. Vexed detectives made only halting progress in identifying possible suspects. Investigators long said it was likely that not all of the deaths were the work of the same killer. Some of the victims vanished in the mid-1990s. Investigators concluded that an 11th person who disappeared in 2010 from the barrier island community of Oak Beach had accidentally drowned.

Heuermann, who lived across a bay from where the bodies were found, was arrested in July. Prosecutors said a new investigative task force used mobile phone location data and DNA samples to link him to some of the victims. He was charged with killing four of the women: Megan Waterman, Melissa Barthelemy, Amber Lynn Costello and Maureen Brainard-Barnes.

Investigators who searched Heuermann’s home and yard last summer returned to the house last month and spent nearly a week searching it again. They focused their efforts mostly in the basement, according to a lawyer for Heuermann’s wife.

That followed a search in April of a wooded area in Manorville, about 40 miles east of Heuermann’s home, and in the Southampton hamlet of North Sea, where Costilla’s remains were discovered decades ago.

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

Taylor, 20, vanished in 2003 while working as an escort in New York City. Some of her remains were discovered in Manorville that year. Other remains were found during a 2011 search of the beach scrub by the side of Ocean Parkway, the road where the other Gilgo Beach victims were found.

Taylor’s mother, Elizabeth Baczkiel, was at the courthouse for Thursday’s hearing. She held up childhood photos of her daughter but didn’t speak to reporters. Her lawyer, Gloria Allred, read a statement from Baczkiel in which she described her daughter as “loving, compassionate and so funny,” and said she would have made a great mother.

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

Mack, 24, who had been working as an escort in Philadelphia, disappeared in 2000 and was last seen by her family in Port Republic, N.J., near Atlantic City. Some of her skeletal remains were discovered that year in the Manorville woods. More of her remains were found in 2011 during the search around Gilgo Beach.

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

Costilla was 28 when she was killed and had lived in New York City.

A decade ago, Suffolk County prosecutors said publicly that they believed Costilla had been killed by John Bittrolff, an area carpenter who was 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 says he didn’t kill anyone, and his lawyers didn’t immediately respond to phone and email messages seeking comment Thursday.

Heuermann’s lawyer, Brown, said he planned to request the prosecution’s files on Bittrolff.

“Quite frankly, the police department and the district attorney’s office all had the finger pointed at Bittrolff for that murder,” he said.

Marcelo writes for the Associated Press.