California woman pleads insanity in stabbing incident

A California woman who was accused of stabbing a couple last year on Pullman’s College Hill because she thought one of the victims was the “devil” pleaded insanity in court Friday.

Whitman County Superior Court Commissioner Douglas Robinson accepted the mental health defense of 29-year-old Tiffany Dennison.

She has been held at the Whitman County Jail since she was apprehended September 2023 on charges of attempted second-degree murder, first-degree assault with a deadly weapon and possessing weapons capable of producing bodily harm.

Court documents show two people were hospitalized after Dennison attacked them with a chef style knife.

A female victim told Whitman County Dispatch her boyfriend had been stabbed in the back by Dennison.

When officers first arrived, they found the man with a “significant” amount of blood, while Dennison was holding the blade making slicing and poking motions toward him.

Police used a stun gun on Dennison to disarm her before placing her under arrest.

The couple was taken to Pullman Regional Hospital. The man suffered a punctured lung, and stab wounds that hospital staff informed officers narrowly missed major arteries. The woman was treated for gashes as well.

Officers were advised there was a toddler at the residence, that one of the victims is the primary caregiver. Dennison told authorities she stabbed the man because she believed he was the devil, and could not let the child be raised by him.

When Dennison tried to assault the couple further, they defended themselves by using a baby gate and kitchen pots as a shield.

The victims made statements in court Friday, who said they are still deeply affected by the incident physically, mentally and emotionally.

“The attack ended in reality, but it has never ended in my head,” the victim said. “The paranoia runs deep, and it’s not just surrounding Tiffany. I no longer trust any stranger. … I no longer trust my judgment concerning new people.”

Dennison was ordered to remain in custody until her sentencing date next month. She is being held on a $1 million bond.

Pearce can be reached at epearce@dnews.com.