(NewsNation) — A Utah mom accused of killing her husband could have been having an affair, according to multiple unconfirmed reports.

Kouri Richins wrote a children’s book about coping with grief after the death of her husband but was later arrested for allegedly killing her husband by spiking his Moscow mule cocktail with fentanyl.

“There are witnesses that will say that she was in fact having a long-time affair. I have not seen proof of that, in terms of text messaging, love letters, other items that I would want to see to corroborate those rumors. But the rumors are out there. And oftentimes, where there is smoke, there is fire,” Coffindaffer said.

While a motive is not required to be shown under law, Coffindaffer explained that the prosecution could use the fact of an alleged affair to show motive.

As for the book Richins authored, Coffindaffer says both the defense and the prosecution could use it in their cases.

“It’s a kind of a double-edged sword in one respect,” Coffidaffer said. “Certainly if she murdered him and she is convicted of that, if all the facts point in that direction, which right now they are, this book just looks terrible that she would use this horrible scheme to monetarily get money for this murder.”

On the other hand, “I think they’re going to try to use it in terms of the defense to try to show some sense of remorse or some sense that no, somebody who could write a book like this could never do a murder,” Coffindaffer added.