PROVO, Utah (ABC4) – Morgan Henderson said she is terrified of her former boyfriend.

And that fear caused her to lie to authorities after she and Jerrod Baum became suspects in the murders of two teens.

After her arrest, Henderson told police Baum claimed to have killed 18-people and is willing to add her to that list.

Baum is facing capital murder charges in the deaths of two teenagers whose bodies were found in a mineshaft near Eureka.

Henderson pleaded guilty to multiple charges of obstruction of justice and will testify against Baum at his trial.

These latest revelations appeared in a court filing by the prosecution. It requests the statements be allowed during the trial.

Henderson claimed she witnessed the murders of Brelynne “Breezy” Otteson and Riley Powell and is considered the state’s top witness.

In court documents, Henderson said that after the murders, she was afraid of Baum.

After her arrest, she told police “if (Baum) didn’t get a gun, he was just going to stab me in the neck when the cops came.”

Baum allegedly told her he’d “cut my head off” if she didn’t hide Riley Powell’s jeep.

And she claimed Baum told her that “he’s killed 18 people.” Henderson also told detectives that Baum shot someone when he was eight-years old and his first murder happened when he was 13-years old.

The judge placed a gag order forbidding the attorneys from talking outside the courtroom.

But a former prosecutor who is now a defense attorney said those allegations may never be heard by the jury.

“That’s clearly character evidence and character evidence is generally inadmissible, and it will not be admitted,” said Kent Morgan, a former Salt Lake prosecutor.

But in the court filing, the Utah County prosecutor argued the Henderson statements aren’t about Baum’s character but it shows the “psychological control of Ms. Henderson.” and possibly future acts by Baum.

The defense has yet to file a response to these allegations. But from the outset their stragegy is to attack Henderson’s credibility.

Morgan said Henderson’s statements, if allowed by the judge can be risky.

“Prosecutors should be in the business of doing things the right way and not creating grounds for an appeal,” he said.

The judge has yet to rule on this evidence. Meanwhile, the defense has requested the trial be moved outside of Utah County. Baum’s attorneys claimed he can’t get a fair trial there. Judge refused to sign the order to change venue until he gets more information from Baum’s attorney.