A Utah woman allegedly killed her ex-husband's new girlfriend in front of their young children

Credit: Uncredited/AP/Shutterstock

A Utah woman has been arrested after she allegedly shot her ex-husband’s new girlfriend in front of their young children.

On Sunday, Chelsea Watrous Cook, 32, allegedly stopped by her ex-husband’s apartment in Midvale to deliver cold medicine to one of their 3-year-old twins, Fox 13 Salt Lake City reports.

Upon her arrival, Cook was asked to leave by her ex-husband, who was in the parking lot when she entered his home— but she refused, police say.

Instead, the mother of two allegedly locked herself in the bathroom and dialed 911, according to an affidavit obtained by The Salt Lake Tribune.

After remaining in the bathroom for some time, Cook allegedly opened the door and walked towards her coat, leaving her ex to believe she was finally leaving, according to the affidavit.

However, police claim she instead pulled out a gun and fired at her ex’s 26-year-old girlfriend Lisa Vilate Williams, striking her twice in the torso.

“[Cook] then suddenly pulled out a handgun and fired three rounds at the victim,” police wrote in jail documents also obtained by The Salt Lake Tribune. “The victim fell back and landed on the coach.”

Cook’s ex-husband told officers he quickly grabbed the gun from his ex-wife and did his best to give CPR to his girlfriend as his children watched.

During that time, Cook’s ex-husband said Cook “walked over to their children and sat on the recliner chair.”

When she attempted to get up again, the ex-husband allegedly pinned Cook against the wall until police arrived.

Williams was then taken to a nearby hospital where she died, Det. Robert Ungritch with the Salt Lake City Police Department told Fox 13.

RELATED: Who Killed a Fire Chief’s Wife? “The Minute I Heard She Died I Knew She Had Been Murdered”

The Salt Lake City Tribune reports that Cook was arrested and booked into the Salt Lake County jail on suspicion of aggravated murder.

In addition to her current charges, Cook is facing domestic violence charges in a Herriman justice court following an incident that took place last month, according to Deseret News. Cook allegedly caused minor injuries to an adult male at her apartment. She has previously pled not guilty in that case.

It is not clear if she has legal representation at this time or whether she has entered a plea in relation to her aggravated murder charge.

According to her Facebook, Cook worked as a health and yoga instructor at Skyridge High School in Lehi. She studied health education at Brigham Young University.

Following the news of her arrest and her prior assault case, the Alpine School District released a statement obtained by Fox 13.

“This morning we learned about a situation involving one of our Skyridge teachers, Ms. Cook. She was arrested and charged with a serious crime. We know there will be information in the media regarding this incident. we want you to be aware of what we have learned, so we can help you process and provide support to any of you who may be in need.”

“This types 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.”