A 35-year-old former Casper woman pleaded guilty Friday to being drunk and causing a wrong-way head-on collision that killed a 43-year-old Casper mother of two in November 2025 and two months later claimed the woman’s 78-year-old father.
Carissa Westphal, who is free on a $50,000 cash bond and living in Colorado, appeared in Natrona County District Court with her attorney Nathan Jeppsen of Rock Springs. She was dressed in black slacks, purple top and walked with a noticeable limp to stand at a podium before Judge Joshua Eames.
Jeppsen told the court his client agreed to a deal with Natrona County District Attorney Dan Itzen that would have her plead guilty to two counts of aggravated vehicular homicide. Her wrong-way crash killed Mandy Butler on Nov. 7, 2025, and on Jan. 26, 2026 her father Randy Butler died from injuries suffered in the wreck.
In exchange, Itzen agreed to drop a driving under the influence with serious bodily injury charge and two counts of reckless endangering, he said.
“There is no recommended sentence in this matter,” Jeppsen said.
Jeppsen said Itzen would provide the factual basis for aspects of the plea that Westphal could not testify to because they related to the “aftermath of the incident.”
The judge went over the agreement with Westphal, explaining that there was no recommended sentence or agreement on whether sentencing on the 20-year felony vehicular homicide counts would be concurrent or consecutive. He asked her if she understood.
“Yes, your honor,” she said.
In response to a question from the judge, Westphal then pleaded guilty to the two counts of aggravated vehicular homicide.
Under questioning from Jeppsen, Westphal agreed that she had been drinking on the evening of Nov. 7. In a soft voice that was difficult to understand she went through the various drinks she had before getting into her red Nissan Altima and turning onto CY Avenue just after 9 p.m.
The Drinks
The police affidavit in the case states she drank up to three-quarters of a 24-ounce White Claw, two 16-ounce Coors Light beers, and one-half to three-quarters of a red Solo cup of an apple cider alcoholic beverage.
“Were you aware that you were intoxicated?” Jeppsen asked Westphal.
“Yes,” she said.
Westphal agreed she drove the wrong way down CY Avenue and that her actions caused the head-on collision that killed Mandy Butler. She said she later learned Butler’s father died.
“Do you agree that the reason of death was because you were intoxicated?” Jeppsen asked.
“I agree,” she said.
Itzen told the court that when her blood alcohol was tested it showed “she was at 0.189%.”
The legal limit for non-commercial drivers in Wyoming is 0.08%.
Itzen told the court it was clear Westphal’s actions not only claimed Mandy Butler but Randy Butler as well.
“He suffered quite a while after the crash and succumbed to his injuries,” he said.
Eames accepted Westphal’s guilty pleas and said sentencing would be set in two to four months after a pre-sentence investigation.
The judge agreed with a request from Jeppsen to set aside an entire day for the sentencing hearing.
Several members and friends of the Butler family were in the courtroom for the plea hearing.
Bond Continued
Jeppsen asked that the judge continue Westphal’s bond arrangement that has her living with her father in Thornton, Colorado, and using a device that tests her blood-alcohol levels three or four times a day.
Itzen had no objection and Eames agreed.
Facts in the case show Casper Police were called to the 5300 block of CY Avenue near the entrance of Tractor Supply just after 9 p.m. on Nov. 7 and found wreckage from Westphal’s Nissan and Mandy Butler’s Toyota RAV4. There was clear indication the Nissan was heading eastbound in the divided highway’s westbound lane.
Mandy Butler was found pinned inside her vehicle. She was transported to Banner Wyoming Medical Center with multiple injuries and died shortly after arriving at the hospital, according to the police affidavit in the case.
Randy Butler was ejected from the Toyota through the windshield and lay unconscious on the hood. Once at the hospital, he was determined to have massive head trauma, multiple spinal fractures, a fractured left hip, shattered right femur, and several broken ribs on his left side that required several surgeries and placement in the intensive care unit, the affidavit stated.
Westphal was pinned inside the Nissan with injuries to her knee.
“She was conscious, stable, and remained so while extricated from her vehicle,” the police affidavit states.
A witness told police he had to swerve to avoid a collision with the Nissan as he headed westbound on CY Avenue.
After just missing his vehicle, the witness said it continued eastbound in the westbound lane with only its running lights on. The driver said he looked in his rearview mirror and saw the Nissan’s brake lights activate but did not see the collision.
The affidavit records other witnesses who were on the road and witnessed the collision between the Nissan and the Toyota, with the Nissan traveling the “wrong way.”
At the crash site, Westphal “presented slurred speech and inconsistent statements to those questions asked of her,” the affidavit states.
She was informed of her arrest, and a search warrant was obtained for blood samples that were taken at Banner Wyoming Medical Center on her arrival at the hospital.
Dale Killingbeck can be reached at dale@cowboystatedaily.com.
