Rex Heuermann.Photo:Suffolk County Sheriff’s Office

Rex Heuermann, Long Island Serial Killer Suspect

Suffolk County Sheriff’s Office

Rex Heuermann, the man police allege to be the Long Island Serial Killer, allegedly meticulously covered his tracks over the years, using burner phones to contact his victims, fake online identities to track their families, and waiting for his wife and kidsto go out of townbefore committing his next crime.But the 59-year-old architect accused of killing at least three sex workers more than a decade ago made some crucial mistakes, Suffolk County District Attorney Ray Tierney claims to PEOPLE.Tierney says authorities were able to narrow in on Heuermann as their primary suspect using cell tower data, a witness’s description of his Chevrolet Avalanche, and eventually DNA from five hairs found on three of the victims.

“Then as the technology progressed, there’s this thing called mitochondrial DNA [and]  they became more suitable for that,” the district attorney says.

Rex Heuermann’s home.Kyle Mazza/Anadolu Agency via Getty

Crime scene investigators bring out evidence from the home of Rex Heuermann who was arrested as a suspect in the Gilgo Beach serial killings In Massapequa Park, Long Island, New York

Kyle Mazza/Anadolu Agency via Getty

A mitochondrial DNA test can trace a person’s maternal ancestry, but it needs a sample to be compared to. “So the Suffolk County PD and the FBI surveilled” Heuermann, Tierney says, obtaining DNA samples from him and his wife off of objects they discarded.

“Now, we go back and we perform that analysis. Two out of the three hairs on Megan Waterman. One, the mitochondrial DNA profile obtained from that hair matches the defendant. One other DNA profile on that hair matches his wife, such that over 99 percent of the rest of the population can be excluded,” he claimes.

Heuermann also says the hair found on Amber Costello “matched the wife,” as well.

Rex Heuermann’s home in Massapequa Park, New York.Michael M. Santiago/Getty

Law enforcement officials are seen as they investigate the home of a suspect arrested in the unsolved Gilgo Beach killings on July 14, 2023 in Massapequa Park, New York

Michael M. Santiago/Getty

“We know that hair – his hair and his wife’s hair – were found on the girl,” Tierney says. “So that could mean one of two things. There’s transfer, meaning if I come in contact with my wife in the morning and one of her hairs gets on my clothes and then I come in contact with someone else, that hair could fall on them. That’s called transfer. Or if someone comes to my house or comes into my car that I share with my wife and they sit down and it goes directly onto them.”Tierney says investigators are still looking into where the murders were committed.

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“I think he lived this double life,” Tierney claims. “He used the anonymity of phones and computers and our modern life to shield himself or part of himself from the rest of society. He had the part of him that faced the public and the part of him that didn’t. He was disciplined in trying to keep that hidden. Unfortunately for him, and fortunately for the rest of us, he wasn’t successful.”

Heuermann’s next court hearing is in early August, according to the district attorney.

source: people.com