STANISLAUS COUNTY --
Karen Mathews Davis was once praised for standing up to terrorists threats in the 1990s and even wrote a book about it, “The Terrorist in my Garage.”
The details were shocking. The former Stanislaus County clerk recorder wrote that a man ambushed her in her garage, then beat and sexually assaulted her back in 1994.
Roger Steiner was convicted of the crime and spent 18 years in federal prison.
While he was behind bars, Mathews Davis claimed she received two threatening letters.
One in 2013 and another in 2014 while she was running for congress.
But now federal investigators claim she lied about the letters.
“And the intriguing part is the latest story that she admits is a lie sounds a lot like the first story that she testified to under oath,” said Bill Portanova, a former state and federal prosecutor.
Mathews Davis was arraigned in federal court on Thursday. The threatening letters were detailed in the arrest affidavit.
One letter said, “A close up shot to your head or to your husband will be final. You make the decision now to not run for congress.”
After Mathews Davis failed a polygraph, she admitted to investigators that she made the whole thing up.
Now, the claims she made 20 years ago against Steiner are being called into question.
“Depending on how severe the lies are, and whether or not they are directly related to sending an innocent man to prison, she could be going to prison herself for many years,” Portanova said.
He added the allegations could mean more trouble for the former candidate.
Steiner, the man she helped put away, has publicly proclaimed his innocence.
“We don’t know yet whether or not an innocent man spent 18 years in prison,” Portanova said.
Now, Mathews Davis is facing federal charges for the suspected fake letters but more charges could be filed.
“This is a prosecutor's worst nightmare,” Portanova told FOX40.
Mathews Davis was granted $50,000 bond. She’s expected to be back in court in November. If convicted, she could be facing up to five years in prison.