Amber Lynn Costello, a 27-year-old woman originally from Wilmington, North Carolina, was living at 1112 America Avenue in West Babylon, New York, at the time of her disappearance. She stood 4 feet 11 inches tall and had several distinctive tattoos, including “Kaos” on her neck, a butterfly on her lower back, and the name “Margaret” on her leg. While working, she used the aliases “Carolina” and “Mia.”

Costello had a history of heroin addiction. After moving to New York from Clearwater, Florida, she completed a 28-day drug rehabilitation program but relapsed not long afterward.

She lived in the West Babylon home with her sister and two men; all four were struggling with heroin addiction. To support their habits, both Amber and her sister engaged in sex work, advertising their services on platforms such as Craigslist and Backpage. The two men, also users, reportedly helped coordinate meetings with clients. Amber provided both in-call services from the residence and out-call appointments.

When clients arrived at the home, a recurring scam was reportedly carried out by the male roommates. After a client paid Amber, and before any sex acts occurred, one of the men would burst into the room pretending to be her outraged boyfriend. The confrontation would typically intimidate the client, causing him to flee without demanding a refund, allowing the group to retain the payment without providing services.

Her ex-husband, Michael W. Wilhelm of Kannapolis, North Carolina, said their marriage ended due to her drug use. “I just don’t put up with that,” he stated. “I told her to hit the road.”

Amber Lynn Costello was last seen by acquaintances shortly before her disappearance. She is one of the known victims in the Gilgo Beach homicide investigation.

Timeline of Amber Lynn Overstreet Costello’s life, arrests, and disappearance:

February 10, 1983:

• Amber Lynn Overstreet is born in Wilmington, North Carolina.

2000s (early):

• Attends Myrtle Grove Middle School and New Hanover High School.

2000s (early-mid):

• Moves to South Carolina and later uses the name Amber Lynn Wilhelm.

November 14, 2005:

• Arrested under the name Amber Lynn Wilhelm for possession of a Schedule I controlled substance in Beaufort County, South Carolina.

January 30, 2006:

• Arrested again in Beaufort County for possession of narcotics.

2006:

• After her arrests, Amber moves to Florida and marries Donald Costello.

June 26, 2009:

• Arrested for petit theft in Pinellas County, Florida.

December 15, 2009:

• Arrested again for petit theft in Pinellas County. She is accused of shoplifting toothpaste and other small items from Publix in Pinellas Park.
• She tells police she works as an assistant at the Clearwater Library, but the city has no record of her employment.
• Fails to appear in court, resulting in an active warrant for her arrest.

Move to New York & Rehabilitation

December 2009:

• Her sister, Kimberly Overstreet, brings Amber to New York for drug rehabilitation.

Late December 2009 – January 2010:

• Completes a 28-day inpatient rehab program; later lives in a sober house, then moves into 1112 America Ave., West Babylon.

Life in West Babylon

Early 2010:

• Begins advertising on Craigslist and Backpage as “Carolina” and “Mia” to support her heroin addiction. Tattoos: “Kaos” (neck), butterfly (lower back), “Margaret” (leg).

2010:

• Lives with sister Kimberly and two male roommates, David Schaller and Dave Brodsky. Schaller and Brodsky coordinate her client appointments and occasionally run scams by posing as her boyfriend to scare off clients after collecting money.

August 2009:

• Brodsky returns to rehab; Amber remains living with Schaller.

Final Days

September 1, 2010:

• A client repeatedly contacts Amber, eventually offering $1,500 for the night.
• 10:30 p.m., Amber receives the final call — the client says he’s parked down the street.
• Despite Schaller’s warnings, she leaves without her phone, wearing a pink hoodie and jeans.

September 2, 2010:

• Amber is last seen leaving her West Babylon home to meet the client.
• 11:17 p.m., the client’s phone (later traced by investigators) travels from Manhattan to Massapequa Park.
• 11:20 p.m., Amber is picked up by a man in a dark-colored truck, believed to be a Chevrolet Avalanche.

September 3, 2010:

• Amber fails to return home. Schaller calls Kimberly Overstreet, who believes Amber is likely using drugs and does not report her missing.
• Kimberly does not report Amber missing, believing she was likely using drugs or with someone. She feared police wouldn’t take the case seriously due to Amber’s background.

December 13, 2010:

• Amber’s remains are found along Ocean Parkway near Gilgo Beach. She had been strangled and wrapped in burlap.
• She is identified as the fourth victim in the “Gilgo Four.” along with Maureen Brainard-Barnes, Melissa Barthelemy, and Megan Waterman.
  

Investigation and Arrest

2011–2022:

• The Gilgo Beach investigation continues with few leads; Amber’s case remains unsolved for over a decade.

2022

• A joint task force including Suffolk County Police, New York State Police, and the FBI reactivates and focuses efforts using advanced digital forensics.

July 13, 2023:

• Rex Heuermann is arrested and charged with Amber Costello’s murder, along with the murders of Megan Waterman and Melissa Barthelemy.

Phone Analysis:

• Investigators trace burner phone data used to contact Amber and the other three victims to a set of burner phones that often operated in proximity to Rex Heuermann’s home in Massapequa Park and his Manhattan architecture office.

Vehicle Match:

• Witness David Schaller recalls the vehicle used to pick up Amber as a first-generation dark green Chevrolet Avalanche.
• Heuermann owned a 2002 Chevrolet Avalanche, registered at the time of Amber’s disappearance.

DNA Evidence:

• A pizza box discarded by Heuermann in Manhattan is retrieved in early 2023.
• DNA from the crust matches male DNA found on Megan Waterman’s body, and other trace evidence consistent with the Gilgo Four crime scenes.

Statement from Dave Schaller

That nights Dave Schaller and Amber Talked about her date:

“This one guy kept calling, and she said he wanted her for the night. I said, “Did he throw money at you?” “Yea, $1,500.” You know, it just sounded like too much money. 1,500 bucks. The guy called, and I walked to the edge of the property. She gave me a hug. She bounced. She took off. And all I had to do was walk another ten feet, and I would have seen the guy’s f**kin’ car. Like ten more feet. Ten feet… I could have seen a license plate or something. Ten feet killed that girl”

Roommate and the Pimp Dave described her client as a 6-foot-4-inch-man who looks “like an ogre.” and was driving the first-generation Chevrolet Avalanche was the vehicle he believed Costello’s killer was driving

The Lead-Up to Amber Lynn Costello’s Disappearance

On September 1, 2010, an unidentified man contacted Amber Lynn Costello through a prepaid burner phone in response to her online escort advertisement. After she agreed to meet him, the burner phone began traveling from the West Amityville/Massapequa Park area toward her residence in West Babylon, Long Island.

As the client made his way to the house, Costello and her roommate, David Schaller, agreed to execute a scam they had used successfully in the past. The plan was simple: once the client handed over the cash, Schaller would emerge and pose as Costello’s angry boyfriend, prompting the client to flee without receiving any services.

This tactic had become well-known enough in certain circles to generate online chatter. In July 2010, a user identified as “Humiliatrix69” posted on the Long Island Erotic Services forum claiming he had been scammed by Costello. He alleged that after paying $200 for sex, he was robbed by men who stormed into the home. Responses from other users quickly escalated. One, using the handle “Italyrider”, asked for Costello’s address and threatened, “No one from this board needs to be involved. I have friends who can take care of this s—.” Another, named “Morrie”, added, “Tell her we are all coming over there with baseball bats.”

Not long after these threats were posted, a large, middle-aged white male appeared at the West Babylon residence. David Schaller later described the man as an imposing figure—like an “ogre”—standing well over six feet tall, wearing sunglasses, and driving a dark-colored pickup truck with a distinctive triangular feature at the rear.

Schaller attempted his usual “boyfriend ruse,” but hesitated when he saw the man’s intimidating size. The man backed off, claiming he was “just a friend” and added, “Tell her I’ll give her a call,” before leaving.

Shortly afterward, the same burner phone sent Costello a message:
“That was not nice, so I credit for next time.”

On the evening of September 2, 2010, the man began contacting Costello again. This time, he requested that she come to his location, citing discomfort with the presence of a “boyfriend” during their last encounter. During their exchange, he offered her $1,500 for an overnight visit—a figure well above her usual rate.

Following a back-and-forth negotiation, they agreed on a price. The burner phone was again tracked traveling from Massapequa Park to West Babylon.

At approximately 11:20 p.m., Amber Costello left her residence and walked to the client’s vehicle, which was parked around the corner. Shortly afterward, David Schaller noticed a dark-colored truck passing by the house. Amber was never seen again.