(CNN) - Rebekah Heath is a research librarian by day, amateur detective by night.
Her sleuthing came to a satisfying conclusion this week when authorities confirmed a shocking discovery she made last October about the cold case known as the Bear Brook murders.
"I still can't believe it," Heath said Friday.
Officials revealed that they had identified three of the four victims who were found in barrels in 1985 and 2000 in Allenstown, New Hampshire. The woman was 24-year-old Marlyse Elizabeth Honeychurch, who also went by Marlyse McWaters, among other names. Two of the three girls were 6-year-old Marie Elizabeth Vaughn and 1-year-old Sarah Lynn McWaters, both daughters of Honeychurch.
It was an answer to a question that had remained a mystery for decades. Authorities on Thursday said the breakthrough was a result of information from relatives, DNA testing, genealogy research — and the diligent research of Heath.
Her first lead didn't go anywhere
In January 2017, investigators announced that a man named Bob Evans had likely killed the four female victims discovered in Bear Brook State Park. In August of that year, they announced that "Bob Evans" was an alias for Terrence "Terry" Rasmussen.
Rasmussen went by many names over the years. He was linked to the 1981 disappearance of a woman in New Hampshire that he was thought to be dating and was serving time for the murder of his wife in California when he died of natural causes in 2010.
Though investigators had identified Rasmussen as the man who likely killed the four Bear Brook victims in 2017, the victims' identities were still a mystery.
For years, helping connect people to their missing loved ones had been a hobby of Heath's. Combined with her interest in the Rasmussen case, she got to work on trying to find potential matches for the victims in November 2017.
She scoured ancestry message boards for terms like "California," where Rasmussen had been arrested, or "missing sister" in hopes of finding a relative of the victims. Then she began compiling a list of names.
"I would just go through that list and then I would start searching to see if they had public records, if the person was alive, see if I could find any record for their existence," Heath said. "If not, then I would pursue it a little further and reach out to the person who had originally posted looking for the loved ones."
Heath said she found a posting from around 1999 about a relative looking for Sarah McWaters and her mother Marlyse McWaters. As she conducted further searches for Marlyse McWaters, Heath came across other relatives looking for the same woman. It turned out McWaters was also the mother of a girl named Marie Vaughn.
In a Facebook group about the Rasmussen case, Heath asked whether those missing people could be the victims found in Allenstown, but she didn't get much of a response. So, she dropped it.
She followed up a year later
About a year later, Heath, who lives in Connecticut, was listening to a New Hampshire Public Radio podcast about the Bear Brook murders when information about the victims reminded her again of the woman looking for Sarah McWaters on that ancestry message board.
"At that point I was like, I need to reach out to this woman," Heath said.
The listing contained an email address, so Heath said she tried to match the address to a Facebook profile. Heath reached out to one woman asking whether she was the same person who had made the ancestry posting.
Within minutes, Heath received a response. It was her.
Heath asked the relative if she had any more information about Sarah and Marlyse McWaters. The woman started sharing more details, including that Marlyse had married a man with the last name Rasmussen.
"Right there, my stomach jumped," Heath said. "It just rocked. I knew right away. There's no way that a woman goes missing with those children with a guy with that last name, Rasmussen. It's just way too coincidental."
Heath didn't say anything to the relative of Sarah McWaters about Rasmussen's criminal history just yet, but she said she began reaching out to relatives of Marie Vaughn. Vaughn's relatives told Heath that Vaughn's mother had left California with a man named Terry.
It all came together in the same week
Within two hours, Heath said she was on the phone with law enforcement in San Bernardino, California. Those authorities quickly turned the information over to investigators in New Hampshire who were already examining DNA research based on information from the family of Marie Vaughn and other genetic databases.
Through advances in DNA technology, investigators were able to obtain DNA profiles of the degraded remains from the barrels. Barbara Rae-Venter, a genetic genealogist who also helped crack the Golden State Killer case, was able to confirm the identities of the victims via searches through DNA databases, according to New Hampshire Associate Attorney General Jeffrey Strelzin.
That, plus the information that came in from Heath and the DNA samples from Sarah McWaters' family, allowed them to make the final determination.
"Her work and our work converged, and it turns out that she was correct," Strelzin told CNN. "She did some great work on the case and some great sleuthing."
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