What we know about the women known as the 'Gilgo Four'

Rex Heuermann has now been charged with killing four women whose bodies were discovered bound with belts or tape and wrapped in burlap along a stretch of Long Island's Gilgo Beach in 2010.

A married father accused by authorities of leading a double life, Heuermann had faced three counts of first-degree murder for the killings of Melissa Barthelemy in 2009, and Megan Waterman and Amber Costello the following year, according to the Suffolk County district attorney. He has pleaded not guilty and is being held without bail.

The 60-year-old New York architect also has been charged in the disappearance and killing of a fourth woman, Maureen Brainard-Barnes, whose remains were found near the same spot, prosecutors said Tuesday. He had been identified as a prime suspect in the killing since his arrest in July.

Heuermann pleaded not guilty Tuesday morning to the superseding indictment charging him with murder in the second degree in the death of Brainard-Barnes.

Heuermann "has maintained his innocence from day one," his defense attorney said after he was charged in the fourth killing.

"He said, 'I'm not guilty of these charges,'" defense attorney Michael Brown said. "He's looking forward to fight these charges and we're doing that. We're going to continue to prepare."

Heuermann was first identified as a potential suspect in early 2022, shortly after a multi-agency task force was formed to examine cold cases involving nearly a dozen sets of human remains found along Long Island's South Shore between 2010 and 2011, including the "Gilgo Four."

"The grand jury investigation of the so-called Gilgo Four is over. It has been concluded," Suffolk County District Attorney Ray Tierney said Tuesday, noting that the same panel will continue looking into other murder cases.

Gloria Allred, a victims' rights attorney representing Barthelemy, Brainard-Barnes and Waterman family members, said it is "long overdue to provide justice for vulnerable women who are missing and murdered."

Allred said it's up to a jury "to decide if this defendant will be found guilty of the murder of Maureen and the murder of other women for whom the defendant has been indicted."

Here's what we know about the deaths of those four women:

Brainard-Barnes was 25 years old and believed to be a sex worker when she was last seen on July 9, 2007. She had called a friend in Connecticut, where she lived, and said she had an "out call," according to Suffolk County police.

The young woman was reported missing by a friend to the Norwich Police Department in Connecticut on July 14. Her remains were found on December 13, 2010, on the north side of Ocean Parkway, near Gilgo Beach.

She is believed to be the first Gilgo Four victim.

Authorities identified Heuermann as a suspect in early 2022 using cell phone data, witness descriptions and other information, and obtained a sample of his DNA from leftover crust in a pizza box he threw out.

Investigators found the DNA of Heuermann's wife on a leather belt that was used to restrain Brainard-Barnes, according to an indictment.

She had been restrained by three leather belts, one of which was used to tie her feet and ankle legs together, the indictment states.

Heuermann's wife and her two children were in Atlantic City at the time of the killing of Brainard-Barnes, according to a bail application.

Tierney described victim Brainard-Barnes as an "intellectual" and "artistic."

"She was a devoted sister, a devoted mother, a devoted daughter, and she's sorely missed by those that loved her," Tierney said.

Brainard-Barnes's family called the latest indictment "an important chapter in the long pursuit of justice."

"It has been 16 years since the last time I saw my sister, 16 years since I heard her voice, because 16 years ago, she was silenced," Melissa Cann said after Tuesday's court proceeding.

Cann, 39, described her sister as a loving mother, sister and friend.

"Maureen would never get the chance to show the world how talented she was," her sister said, choking up. "My family will never get the chance to know who Maureen would be today because her life was tragically taken."

Nicolette Brainard-Barnes was only 7 years old when her mother was killed. She said the loss changed the trajectory of her life.

"While the loss of my mom has been extremely painful for me, the indictment by the grand jury has brought hope for justice for my mom and my family," said Nicolette Brainard-Barnes, now 24.

Cann told CNN in 2011 that she desperately tried to solve the mystery of her sibling's disappearance, scouring her emails and phone records, and staying in touch with families of the other victims.

Cann said her sister worked a seasonal telemarketing job and turned to escort services in desperation when left unemployed and facing eviction.

Barthelemy was 24 years old when she was last seen on July 12, 2009, in the basement apartment where she lived in the Bronx, according to the Suffolk County police website on the Gilgo killings.

On the night she was last seen, Barthelemy, a sex worker, told a friend she was meeting a man and would be back in the morning, according to the police website.

Barthelemy's mother reported her missing on July 18. Records for her cellphone showed activity in Manhattan as well as Freeport, Massapequa and Lindenhurst on Long Island.

In July and August 2009, according to a bail application for Heuermann, Barthelemy's phone was used by a man to make taunting calls to the victim's family.

Steve Cohen, who was an attorney for Barthelemy's mother at the time, told CNN the caller said he killed her daughter.

"Do you think you'll ever see her again?" the unidentified male caller asked Barthelemy's sister on August 26, 2009, according to Cohen. "You won't. I killed her," he said and hung up.

In another phone call, just days after Barthelemy disappeared, Cohen said the unidentified male caller referred to the victim as a "whore" in a short conversation with her then-15-year-old sister.

In one call, the man described in graphic detail to the victim's sister what he had done sexually to Barthelemy, according to Cohen.

Barthelemy's remains were the first set of female remains found in bushes along an isolated strip of waterfront property. At the time, authorities were searching for another missing woman, Shannan Gilbert, a 23-year-old from Jersey City, New Jersey, who hadn't been seen since May 2010.

"I still don't sleep through the night thinking about all of it," Lynn Barthelemy, the victim's mother, told CNN in 2011.

She said she jotted down everything she learned about the case in a notebook and spoke regularly with families of other victims.

Investigators believe Barthelemy was the second of the women to be killed.

Waterman was 22 years old when she was last seen on June 6, 2010.

A resident of Maine, Waterman was last seen by her family boarding a Concord Trailways bus heading from Maine to New York, according to Suffolk County police.

She was a sex worker, police said. At 1:30 a.m. on June 6, she left the Holiday Inn Express on Long Island to meet a client, according to police.

Waterman was reported missing in Maine on June 8. Family members said it was unusual for her not to check on the daughter Waterman had left in their care.

Her body was found on December 13, 2010, near Gilgo Beach.

Waterman's family at one time used funding from a nonprofit human rights organization to hire a team of private investigators to help search for her.

Dottie Laster, a member of that team, told CNN in 2011 Waterman sounded starstruck when she called her mother to boast that her clients included doctors, lawyers and law enforcement officers.

Costello was 27 years old and living on Long Island when she was last seen. She struggled with a heroin addiction and worked as an escort to help support her habit, according to Suffolk County police.

She was was last seen leaving her home on September 2, 2010, to meet a client. Her remains were found on December 13, 2010, near Gilgo Beach. She is believed to be the fourth victim.

Witnesses told investigators that the client she met the day she went missing had been at her home previously. They described the man as "a large, white male, approximately 6'4" to 6'6" in height" with "big oval style" glasses. A witness also said the man resembled an "ogre." Heuermann's bail application noted the description from these witnesses in 2010 matched Heuermann.

Costello's sister, Kim Overstreet, told CNN in 2011 that she took out an ad hoping to catch the killer. The ad implored other women who work as escorts to call Overstreet. She wanted them to tell her if they ever encountered a client who was threatening or just didn't feel right.

"What happened to Amber eats at me every day," Overstreet said at the time. "Finding out who did this consumes me. I stay up all night doing research and trying to re-trace her last steps."

Witnesses also said the man drove a first-generation Chevrolet Avalanche - a key clue that prosecutors said helped lead them to Heuermann.

This story has been updated with additional information.

CNN's Steve Forrest, Artemis Moshtaghian, Nicki Brown, Mark Morales and Brynn Gingras contributed to this story.