If you’ve been hooked on Netflix’s latest drop, “Gone Girls: The Long Island Serial Killer,” you’re probably curious about Amber Lynn Costello and the chilling story behind her death. Back in September 2010, Amber Lynn Costello stepped out of her West Babylon apartment to meet a client, never to return. A few months later, the discovery of her remains, along with those of three other women, near Gilgo Beach stunned Long Island. Her death became a chilling piece of the Gilgo Beach Serial Killings puzzle—a case that stumped cops for years. Only a revamped task force and some slick digital detective work unraveled the case, leading to the identification of a suspect after more than a decade. At TV Acute, we’re diving deep into her case—how she tragically lost her life, who’s accused of killing her, and why this mystery took years to crack. Let’s break it all down in a way that’s easy to follow and keeps you hooked!
Who Was Amber Lynn Costello?
Amber Lynn Costello came into this world on February 10, 1983, bringing a burst of happiness to her parents, Alfred P. Overstreet Jr. and Margaret Anne Sasse. Growing up in Wilmington, North Carolina, she shared a tight bond with her sister, Kimberly Overstreet. Amber possessed a generous heart, willing to assist anyone in need without any hesitation. Her own tough times only made her more compassionate, and she always tried to lift others up.
However, life presented her with unexpected challenges. Amber dreamed of lasting love, but both of her marriages ended in divorce. On top of that, she battled drug addiction, a fight that shaped much of her later years. Determined to turn things around, she leaned into her faith, got active in her church, and even moved to New York in 2009 with Kimberly’s help. Her sister got her into rehab, and for a while, Amber lived in a sober house before settling into her own place in West Babylon, New York. But addiction’s grip was strong—she relapsed and, to fund her habit, started working as an online escort. That decision, sadly, set the stage for her heartbreaking end.
The Night Amber Disappeared
Fast forward to September 2, 2010. Amber, then 27, was living with roommates in West Babylon. That evening, a client dangled a tempting offer—$1,500 for a meet-up, way more than her usual rate. She told her roommate Dave Schaller she’d be back soon and stepped out without her phone or purse. That was the last time anyone saw her alive.
When Amber didn’t come back, Dave got worried fast. He called Kimberly down in North Carolina, but she figured Amber might’ve checked into rehab again since no one could reach her. Months passed with no word. Then, on December 13, 2010, a shocking discovery upended everything. A police dog training along Ocean Parkway near Gilgo Beach stumbled across human remains in a burlap sack. Soon after, they found three more bodies in the same spot. DNA tests in January 2011 confirmed one set of remains belonged to Amber Lynn Costello. An autopsy showed she’d been strangled—a grim clue that linked her death to the others.
This wasn’t just a random discovery—it kicked off the infamous Gilgo Beach serial killer case. Amber’s murder, along with the others, sent chills through Long Island and left everyone asking: who did this?
Clues That Took Years to Connect
Right from the start, police had some leads. They found hair at the crime scenes where Amber and the other three women—later dubbed the “Gilgo Four“—were dumped. The bodies were all wrapped in burlap, strangled, and left in the same stretch of Ocean Parkway. It screamed one killer. However, due to the lack of a suspect to match the DNA to, the case faced significant obstacles.
Dave Schaller gave cops a solid tip early on. He said Amber’s client called her three or four times that night, with the final call around 10:30 p.m. before she left. Dave described the guy as huge—“an ogre,” he called him—standing 6’4” or 6’6” with bushy hair, driving a dark, first-generation Chevy Avalanche. That’s a pretty specific picture, right? Yet, back then, police couldn’t pin it on anyone. Years passed without any answers, and the trail remained unexplored.
Everything changed in 2022 when a new police commissioner, Rodney Harrison, took over. Rodney Harrison was determined not to let this case languish. Rodney put together a fresh task force and had them digitize 12 years of evidence—think old files, interviews, and clues buried in paperwork. They combed through it all and zeroed in on Dave’s statement from way back. That Chevy Avalanche detail? It stuck out. They figured a big guy like that might own a car to match. Plus, they knew the killer used burner phones, and those phones pinged in Massapequa Park and Midtown Manhattan—areas tied to Amber and the other victims, who’d all worked as escorts.
Enter Rex Heuermann: The Suspect
The task force hit paydirt on March 12, 2022, when they ID’d a suspect: Rex Heuermann. Who’s he? A 61-year-old architect from Massapequa Park, married with two kids, running a firm in Midtown Manhattan. Sounds like your average family man, but the evidence painted a darker picture. Cops tracked his moves and matched burner phone activity to his locations. They dug deeper and found anonymous email accounts he allegedly used to contact escorts, including Amber.
The decisive moment occurred when they discovered his DNA in a pizza crust he had thrown away in January 2023. It matched the hair found on the victims—bam, game over. In July 2023, after 13 long years, police arrested Rex and charged him with Amber Lynn Costello’s murder, along with Megan Waterman’s and Melissa Barthelemy’s. The charges kept piling up—Maureen Brainard-Barnes in January 2024, then Sandra Costilla (1993), Jessica Taylor (2003), and Valerie Mack by December. Seven murders total, and Rex has pleaded not guilty to every single one. As of now, March 31, 2025, the investigation’s still rolling, and who knows what else they’ll uncover?
How Amber’s Case Broke Open
Amber Lynn Costello’s murder might’ve stayed unsolved if not for her roommates. Dave and another guy, Bear Brodsky, had run-ins with a creepy client before she vanished. They told cops about a tall, intimidating dude in a Chevy Avalanche who’d spooked Amber once. They’d even chased him off, but when she went missing, they gave police that same description. The matter remained unresolved for years, until the 2022 task force made the connection. That vehicle and Dave’s story pointed straight to Rex Heuermann.
Netflix’s Gone Girls: The Long Island Serial Killer, which dropped on March 31, 2025, shines a spotlight on this. The three-part series, directed by Liz Garbus, walks you through the whole saga—how the Gilgo Four, including Amber, were found and how dogged police work finally nabbed a suspect. It’s not just about the killings; it digs into how society brushed off these women because they were escorts and how that might’ve slowed things down. You’ll hear from Amber’s roommates, family, and even a relative of Rex’s, making it a must-watch for anyone hooked on this case.
As of right now, Rex’s trial date isn’t set, but the case is far from over. Amber Lynn Costello’s murder rocked Long Island, and with every new charge, it’s clear this story’s got legs. Want more details? Check out Gone Girls on Netflix or hit up our site for the latest updates.
Read More: Where is Rex Heuermann’s Wife ‘Asa Ellerup’ Now?
