(CNN) -- Reporter Francis Scarcella walked into the Northumberland County Prison in Sunbury, Pennsylvania, with plenty of questions for the woman accused along with her husband of luring a man with a Craigslist ad, then killing him.
He walked out with a bombshell of a story that's sent police and the press alike scrambling for answers.
Miranda Barbour told Scarcella, a reporter for the Daily Item newspaper in Sunbury, that she'd killed before. And not just once or twice.
"She said, she has, you know, done this before," Scarcella told CNN affiliate WNEP of his Friday interview with the 19-year-old murder suspect. "And I said, 'What's the actual number?'"
"And she said, 'Under a hundred,'" Scarcella told the station. Barbour said she had stopped counting at 22 killings, according to Scarcella's story in the Daily Item.
"She kind of floored me," Scarcella told CNN affiliate WBRE.
Authorities haven't yet corroborated any of Barbour's claims, including statements that she was involved in Satanism. Her alleged confession has raised questions among attorneys, missing persons experts and even a representative of the Church of Satan, the nation's largest satanic body.
"Thorough investigation will likely demonstrate that this cult story is fiction," said Peter Gilmore, the New York-based head of the Church of Satan.
In the one case in which authorities say they have pinned down Barbour's involvement, she and her husband, Elytte Barbour, 22, are accused of killing 42-year-old Troy LaFerrara, who police say responded to a "companionship" ad placed by Miranda Barbour on Craigslist.
Police say Elytte Barbour strangled LeFerrara in the front seat of her red Honda CR-V while Miranda Barbour stabbed him at least 20 times in November 2013.
LaFerrara's body was found the next day in the backyard of a home in Sunbury, a small city about 100 miles northwest of Philadelphia.
The last number dialed on his cell phone led police to the Barbours, according to authorities.
The couple, married for only three weeks at the time of the slaying, just wanted to kill someone together, police said. They moved from North Carolina to Pennsylvania after they tied the knot.
Elytte Barbour told police at the time that he and his wife had tried to kill others, but the plans didn't work out.
"I remember everything," the Daily Item quoted Miranda Barbour as saying, adding the November killing was the couple's first. "It is like watching a movie."
Both Barbours face several charges in LaFerrara's death, including murder. Despite Miranda Barbour's statements to Scarcella, both have pleaded not guilty.
While she said LaFerrara's killing was the couple's first, Barbour claimed she began killing when she was 13 and involved in a satanic cult, Scarcella reported.
"I can pinpoint on a map where you can find them," he quoted her as saying of the bodies.
Claims raise doubts
Investigators are looking into Barbour's claims, but have not yet corroborated her involvement in any other killings, according to officials.
Sunbury Police Chief Steve Mazzeo told CNN that investigators have been in contact with the FBI and law enforcement in some of the states where Barbour has lived.
"We investigate all leads just because that's the proper protocol to follow through," Mazzeo said.
The father of Barbour's 1-year-old child is dead, and Sunbury police have said that is part of their investigation.
Authorities also are looking closely at Barbour's claims that she was involved in Satanism, according to another law enforcement source close to the investigation.
Gilmore, of the Church of Satan, said his church has a "law and order philosophy" that does not condone killing. He said the church has had no contact with Miranda Barbour or her husband.
Monica Caison, the founder of a missing persons center in North Carolina -- where the Barbours once lived -- said she started getting phone calls about Barbour's claims Sunday night.
But she said Barbour will have to be questioned extensively by investigators before those claims can be put to the test.
"They've got to find locations and sectors for the cases," said Caison, founder of the Community United Effort Center for Missing Persons. "You can't just say you've killed 22 people between this region and that region. You've got to give a town or something that only police or an organization like us would know."
She said she doubts Barbour's claims.
"That's a lot of people to kill in such a short time, and being so young and never making a mistake, I'm hard pressed to believe that amount," she said.
If Miranda Barbour did kill more than 22 times, she would be an unusual example of a female serial killer, said CNN legal analyst Danny Cevallos.
"Statistically and from an academic perspective, a female serial killer is exceedingly rare," he told CNN on Monday.
Barbour's attorney, public defender Edward Greco, told CNN he didn't know she was planning to give the interview. He declined to comment on her claims.
Getting the interview
told WNEP he got the interview after Barbour sent him a letter saying she wanted to talk.
Scarcella told CNN on Sunday that he was not allowed to bring a notepad or any other recording device into the interview. He said police allowed him to listen to the interview after it was conducted.
In his interview with WNEP, Scarcella described Barbour as "very meek, very mild" with a "very low voice."
"She never hesitated once," he told the station. "She never gave the impression of it was a rehearsal."
Scarcella said he eventually asked if she had any remorse.
"And she said, 'None,'" Scarcella told WNEP.
But that's not what Scarcella said he found most surprising.
That would be, he said, "the fact that she said that if she got out she would do it again."
CNN's Daniel Burke, Haley Draznin, Susan Candiotti and Chris Welch contributed to this report.
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