Chelsea Watrous Cook has pleaded guilty to aggravated murder in the 2018 slaying of her ex-husband's new girlfriend

Teacher Lured Ex-Husband Away from House Before Killing New Girlfriend in Front of Twin Daughters

Cook has pleaded guilty to aggravated murder, aggravated burglary, three counts of firearm-related felonies and two counts of misdemeanor charges of committing a violent offense in front of children for the November 2018 death of 26-year-old Lisa Vilate Williams, KUTV, Desert News, the Salt Lake Tribune report.

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On Nov. 25, 2018, Cook arranged to give ex Travis Cook cough medicine for the couple’s children in the parking lot outside his apartment building.

Image zoom Lisa Vilate Williams gofundme

But police found CCTV footage that showed Cook sending text messages in the apartment building’s hallway, according to a probable cause affidavit obtained by local station KUTV and the Tribune.

“Shortly thereafter, Mr. Cook exits his apartment and once he is out of sight [Chelsea Cook] enters the apartment without knocking,” according to the affidavit, KUTV reports.

Travis Cook told investigators that when he reentered the apartment, he found Cook inside. He said he asked her to leave but she refused. She then locked herself in the bathroom for 15 seconds before coming out to get her coat, after which she allegedly pulled out a handgun and fired multiple times upon her husband’s girlfriend, Williams, who later died from her injuries.

At the time she was fatally shot, Williams was decorating a Christmas tree with the 3-year-old twins her boyfriend and Cook shared.

According to her Facebook page, Cook worked as a health and yoga instructor at Skyridge High School in Lehi.

Williams and Travis Cook had been dating for six months before her death.

Williams’ family told the Associated Press that Chelsea Cook had allegedly been harassing the new girlfriend on the phone, online and in person.