Utah Teacher Allegedly Shoots, Kills Ex-Husband's New Girlfriend in Front of Her Own Twin Children

Chelsea Watrous Cook
Salt Lake County Jail

Chelsea Watrous Cook, 32, was booked into jail on a charge of aggravated murder.

A Utah high school teacher allegedly shot her ex's new girlfriend twice in front of her own children on Sunday.

Chelsea Watrous Cook, 32, went to her former husband's apartment in Midvale, Utah, to bring cold medicine for one of her 3-year-old twins, according to police. Her ex, who was not identified in court papers, was in the parking lot when Cook showed up and immediately demanded that she leave. Instead, Cook allegedly locked herself in the apartment's bathroom and refused to leave, The Salt Lake Tribune reported.

Cook then dialed 911 and remained locked in the bathroom on the phone with a dispatcher for a while, according to the Tribune. Eventually, she left the bathroom and appeared to go put on her coat, the documents state.

But, police said, she reached into the coat's pocket and pulled out a gun, firing at her ex's girlfriend, 26-year-old Lisa Vilate Williams, multiple times. Williams was hit twice in the torso, knocking her onto the couch. 

The ex wrestled the gun away from his former wife and tried to save Williams, as the young children looked on, according to police. Cook, meanwhile, slumped into a chair near the children. 

When she tried to get up from the chair, the ex grabbed Cook and pinned her against a wall, which was where police found them when they arrived, the documents state. Williams was taken to a local hospital where she later died. Cook was booked into Salt Lake County Jail on a count of aggravated murder. She has not yet entered a plea.

Cook already faced separate charges of domestic violence stemming from a different incident, according to the Deseret News. She had pleaded not guilty in that case.

Cook had worked for the Alpine School District as a health and yoga teacher. In a statement Monday, the district said: "This morning we learned about a situation involving one of our Skyridge teachers, Ms. Cook. She was arrested and charged with a serious crime. ... This type of news is hard to comprehend and we want you to know that teachers, counselors and your parents can help provide support in this difficult time."