On the Hunt for a Monster: How Police Unraveled the Long Island Serial Killer Mystery After Years of Terror

Mar. 15, 2025

Maureen Brainard-Barnes; Melissa Barthelemy; Megan Waterman; Amber Lynn Costello.Photo:Suffolk County Police Department; Barthelemy family; Suffolk County Police Department (2)

Suffolk County Police Department; Barthelemy family; Suffolk County Police Department (2)

Shannan Gilbertwas working as an escort on May 1, 2010, when she vanished without a trace after visiting a client in the gated community of Oak Beach on Long Island, N.Y.

Before she fled from the man’s home, she called 911 and told an operator that somebody was after her. She ran to an elderly neighbor’s home and asked for help before darting off in the early morning light.

However, when police finally showed up, Gilbert, 23, was nowhere to be found.

A search began that led to the shocking discovery of four bodies —Melissa Barthelemy,Amber Costello,Megan WatermanandMaureen Brainard-Barnes— in December 2010. All four women were in their 20s and worked as online escorts, like Gilbert. They disappeared between 2007 and 2010.

The shocking discoveries continued. Two months later, in March 2011, authorities found the remains of more bodies along the beach.

Shannan Gilbert.Jersey City Police

Jersey City Police

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Police also discovered the remains of 34-year-oldKaren Vergata, who went missing in 1996. Some of Vergata’s remains were found on Long Island’s Fire Island on April 20, 1996. More body parts were found on Long Island’s Tobay Beach in April 2011.

Then, in Dec. 2011, the skeletal remains of Gilbert, whose disappearance sparked the search along Ocean Parkway, were found in a marsh near Oak Beach. While the details of how she vanished are murky, police believe Gilbert somehow got lost in the inhospitable marshland and died accidentally — either of exposure or accidental drowning. Her family has long suspected that she was murdered.

Rex Heuermann.James Carbone-Pool/Getty Images

James Carbone-Pool/Getty Images

Heuermann was taken into custody in July 2023, when a task force set up to find the killer arrested the now 61-year-old architect and father of two after DNA evidence allegedly linked him to the murders of Barthelemy, Costello and Waterman.

Sandra Costilla; Jessica Taylor.Suffolk County Police Department

Suffolk County Police Department

Investigators also allegedly found hundreds of internet searches about raping and torturing women, child sex abuse material and violent pornography as well as searches for his victims and their families.

He was charged with second-degree murder in the death of Brainard-Barnes in January 2024 after DNA evidence linked him to the crime.  Five months later, he was charged with killing Taylor, whose remains were found along Ocean Parkway and Manorville, and Sandra Costilla.

Valerie Mack.suffolk county police department

A hair from Heuermann’s then preschool daughter Victoria was also discovered in the sealed garbage bag where some of Mack’s remains were found in Manorville, per the indictment.

Heuermann is currently being held at the Suffolk County Jail.

He has pleaded not guilty.

Gone Girls: The Long Island Serial Killer, begins streaming on Netflix on March 31.

source: people.com