Former Utah teacher charged with murder in death of ex-husband’s girlfriend

Chelsea Watrous Cook.

MIDVALE, Utah — A former Utah teacher has been charged with murder in the death of her ex-husband’s girlfriend. 

Chelsea Watrous Cook, who taught health classes at Skyridge High School in Lehi,  was charged Wednesday with aggravated murder as a first degree felony and other counts related to the incident.

The charges against Cook stem from November 25, when Lisa Vilate Williams, 26, was shot and killed.

Charging documents state Cook had told her ex-husband she would be coming over to drop off cold medicine for the estranged couple’s twin 3-year-old children.

The man asked Cook to wait outside for him, and police say surveillance footage shows Cook sneaking into his apartment after the man went downstairs to meet her in the parking lot.

The man returned to find Cook inside his living room with Williams and the two children. He asked Cook to leave and she refused, so he called 911. The charging documents state Cook then walked into a bathroom and locked herself inside.

About 15 seconds later she exited the bathroom and walked toward her coat, which is when her ex-husband heard gunshots.

Williams was shot and killed, and police say the two young children were present when she was shot.

The man ultimately pinned Cook against a wall until police arrived at the scene.

Police say they recovered four 9mm casings from the scene along with a 9mm Taurus G2C handgun.

A medical examiner states Williams was shot three times and the cause of her death was homicide.

Cook is charged with one count of aggravated murder as a first-degree felony, one count of aggravated burglary—domestic violence as a first degree felony, three counts of felony discharge of a firearm, and two counts of violence in the presence of a child.

Support is available 24/7 in Utah for those dealing with domestic violence. Visit the Utah Domestic Violence Coalition online or call 1-800-897-5465 for resources and assistance. In an emergency, dial 911.