Long Island Serial Killer: A Victim's Roommate Speaks

In the 10 years she'd been working in prostitution, 27-year-old Amber Lynn Costello had developed a system to minimize the danger. She arranged dates through her roommate Dave Schaller's cellphone, and sometimes had him wait in the next room to fend off violent clients, or watch as she was picked up outside their apartment. Now for the first time Schaller speaks about the calls Costello received on September 2, 2010, the night she disappeared, another victim of the suspected serial killer terrorizing Long Island.

In Costello and Schaller's system, an "incall" was preferable to an "outcall," but after the stranger called several times that evening, Schaller tells Newsweek's Christine Pelisek, Amber "felt comfortable with him." So after the the final call at 10:30—and the settlement on the unusually high price of $1,500—Amber left the modest gray-shingled house she shared with Schaller in West Babylon, New York, wearing a pink hoodie and jeans.

When Amber didn't come home the next morning, Schaller called her sister, Kimberly Overstreet. Amber and Kimberly grew up in North Carolina together, and remained quite close. "We didn't live the American [Dream] childhood," says Overstreet. "We watched our family struggle through alcohol addiction and sickness." Amber struggled as well. She was a promising student but became involved with drugs as a teenager, and as an adult fought to overcome an addiction to heroin. "She was beaten down," says Overstreet. She was also sexually molested by a neighbor when she was 6 years old, an incident that caused their mother to have a breakdown.

Later, when Amber ran into debt in Florida, her sister bought her a plane ticket to New York, where she spent a short time in rehab before falling back into heroin use and prostitution. The sisters were close, but when Schaller called her to tell her Amber hadn't returned, six months after she had bought her sister a ticket to New York, Kimberly told him not to worry.

Costello's family never reported her missing. But even when families do report disappearances, police don't always make priorities of people living in such precarious circumstances. When a sister of Maureen Brainard-Barnes alerted police after she disappeared in 2007, she was told, "Your sister ran away and doesn't care about anyone." Maueen's was one of the four bodies found in the bushes of Long Island's Ocean Parkway. All four women had been working as prostitutes.

Cases involving prostitution can be among the most difficult to solve. Even when a case does get going—and there are significant obstacles to that happening—they often turn cold. The victims frequently use false names (Costello advertised herself as "Carolina") and are survived by witnesses who themselves often live on the margins of society. N.G. Berrill, a forensic neuropsychologist who has studied Joel Rifkin—a serial killer who along with Robert Shulman killed more than 20 prostitutes in the same area during the early 1990s—says, "People disappear, and folks don't know the difference."

Schaller recalls how he warned Amber of the danger. "But she never thought anything would happen to her," he says. At just 4-feet-11-inches tall and weighing barely 100 pounds, "She thought she was indestructible."

"It makes me upset" to think of how she died, he says. "As much as I did, it wasn't enough. Look what happened."

Click here to read Christine Pelisek's full report.

Christine Pelisek is staff reporter for The Daily Beast, covering crime. She previously was a reporter at the LA Weekly, where she covered crime for the last five years. In 2008, she won three Los Angeles Press Club awards, one for her investigative story on the Grim Sleeper.