(NewsNation) — Architect Rex Heuermann was charged in the deaths of three of the 11 victims in a string of killings in Long Island from over a decade ago.

In 2010 and 2011, skeletal remains were found along a remote oceanfront highway by Gilgo Beach. Most of the victims were young women who had been sex workers.

In court, Heuermann pleaded not guilty to three counts of first-degree murder and three second-degree charges for the deaths of Melissa Barthelemy, Megan Waterman and Amber Costello. Authorities are continuing to work toward charging Heuermann for a fourth victim, Maureen Brainard-Barnes.

“Rex Heuermann is a demon that walks among us. A predator that ruined families,” Suffolk County Police Commissioner Rodney Harrison said at a news conference Friday.

Suffolk County District Attorney Ray Tierney told reporters Heuermann had seven burner phones. During a 14-month period, Heuermann made Google searches on the Gilgo Beach killings 200 times, Tierney said.

It was discovered that Heuermann looked at “torture porn,” Tierney said, including that of women being abused, raped and killed. Tierney said Heuermann has access to 92 handguns.

Investigators mapped burner phones to cellphone pings from four cellphone towers, Tierney said. They called this area “the box” and it led them to Heuermann.

More than 300 subpoenas and search warrants were issued during the course of officials’ investigation, Tierney said.

According to Heuermann’s bail application, he was identified as a suspect through DNA left on a pizza crust thrown out in a Manhattan trash can. His wife’s hair was also found on three Gilgo Beach victims, according to the application.

Travel records show Heuermann’s wife and kids were out of the state when the killings happened, Tierney said.

Heuermann’s defense attorney, Michael Brown, speaking after Friday’s court hearing, said this evidence is extremely circumstantial in nature, and said his client told him: “I didn’t do this.”

Heuermann was taken into custody in Massapequa late Thursday, after a renewed investigation that identified him as a suspect in March 2022. Detectives linked him to a pickup truck a witness reported seeing when one victim disappeared more than a decade ago.

The families of victims Jessica Taylor and Shannan Gilbert, two other women whose remains were found, were happy to see police accomplishing something, their attorney, John Ray, said.

“Let’s wait and see what it all leads to,” Ray said.

Gilbert’s 2010 disappearance was what triggered the investigation.

Determining who killed the victims, and why, has vexed a slew of seasoned homicide detectives through several changes in police leadership. Last year, an interagency task force was formed with investigators from the FBI, as well as state and local police departments, aimed at solving the case.

The hunt for a suspect in what’s become known as the Long Island serial killer case started more than a year before police released a 911 call made by Gilbert before she vanished in 2010. A 24-year-old sex worker, she vanished after leaving a client’s house on foot in the seafront community of Oak Beach, disappearing into the marsh.

In talking about the bodies near Gilgo Beach, investigators have said several times over the years that it is unlikely one person killed all the victims.

News of Heuermann being taken into custody comes a day after state police responded to a report of skeletal remains found in a wooded area off the Southern State Parkway in Islip. It wasn’t immediately clear if those remains were linked to the Gilgo Beach case.

The mystery attracted national headlines for many years and the unsolved killings were the subject of the 2020 Netflix film “Lost Girls.”

Devan Markham and The Associated Press contributed to this report.