Is Craigslist murder suspect lying about 22 other killings?

Miranda Barbour – the 19-year-old Pennsylvania woman charged along with her newlywed husband with killing a man she lured through Craigslist – said in a jailhouse interview that she’s killed more than 20 other people across the county, but is she telling the truth?

Barbour’s claims are being met with skepticism, but one legal expert tells CBS News’ Crimesider that even if her claims prove false, she may have dug herself an even deeper hole.

“If what she’s saying is not true, she could face criminal charges for having law enforcement agencies spend time and money [to investigate these claims,]” Heather Hansen, a Pennsylvania defense attorney told Crimesider Tuesday.

The 19-year-old is currently jailed, along with her husband Elytte Barbour, for the November 2013 stabbing death of Troy LaFerrara. Miranda Barbour told investigators she met LaFerrara after he responded to her Craigslist ad offering companionship for money. Elytte Barbour told investigators they committed the crime because they wanted to kill someone together, according to court papers.

In an interview with The Daily Item in Sunbury published Saturday night, Miranda Barbour said she has killed at least 22 people throughout Alaska, Texas, North Carolina and California in the last six years as part of her involvement in a satanic cult she says she joined when she was 13.

Following these claims in her jailhouse interview, the FBI’s Philadelphia division issued a statement saying it had been in contact with Sunbury police and “will offer any assistance requested in the case.”

Sunbury police Chief Steve Mazzeo told the newspaper that investigators were aware of Miranda Barbour's claims of involvement in other murders. He said they are "''seriously concerned" and have contacted police in other jurisdictions.

“I think she’s lying,” Pennsylvania defense attorney Hansen told Crimesider. “You can confess to anything you want, but if there’s no evidence of it, she can’t be charged with anything until they find something to corroborate it.”

Barbour reportedly told her interviewer she could "pinpoint" the victims on a map.

Carrie Adamowski, a public affairs specialist with the FBI’s Philadelphia division, told Crimesider it's unlikely Barbour will face federal charges if the claims she made to the newspaper are proven false, but she said she could face charges in local jurisdictions.

The only way she would face federal charges in regards to making false claims is if she is interviewed by the FBI and is proven to have lied to them, Adamowski said.

Hansen said the interview could be extremely detrimental to the Barbours’ defense in the Craigslist case if it goes to trial.

“Not only is she killing herself, she’s killing her husband too,” Hansen said of the interview’s potential effect in court. “All of this is admissible. She voluntarily decided to speak to this reporter.”

“She has backed her attorney into a corner where he has no option other than to put forth an insanity defense and she has provided a lot of hurdles,” she continued.

To successfully argue an insanity defense in Pennsylvania it would need to be proved that the defendant didn’t know right from wrong at the time of the crime.

According to Hansen, that’s a very hard burden to meet, especially when the defendant(s) are alleged to have provided authorities with insight into the planning and execution of the crime.

What’s more likely, says Hansen, is the case won't go to trial and instead, a plea deal will be reached and she will be sentenced to life in prison.

Miranda Barbour said in the jailhouse interview that she wanted to plead guilty at her arraignment, but that her attorney pleaded not guilty for her. She also said that she doesn't want to get out of jail and that she would kill again if released.

“The real horrible part of this is all of the families of missing people – anyone who has a missing family member in any of those states has to be wondering if their loved ones is one of the ones she [claims to have] killed,” Hansen said.