High School Teacher Shoots, Kills Ex-Husband’s Girlfriend, Police Say

LEHI, Utah – As students arrived for classes at Skyridge High School, Monday morning, administrators at the Alpine School District received some alarming news: one of their teachers was arrested on suspicion of murder.

“Just hearing the news is shocking, and (we’re) heartbroken,” assistant to the superintendent, Kimberly Bird said. “It’s been a trying time, something that we’re not used to dealing with.”

Bird says a team of counselors were on hand all day at the school Monday, for both students and teachers who knew Cook.

An email was also sent out to parents, notifying them of the situation.

“We wanted them to be assured that we had resources in place,” Bird said. “We look at school teachers as they’re trusted individuals, and we want to maintain that that’s really who our teachers are. It’s unfortunate when something as rare as this happens.”

Police say Cook went to her ex-husband’s Midvale apartment Sunday to deliver some cough medicine for one of their twin 3-year-old children.

According to arresting documents, Cook was at some point asked to leave. She then locked herself in a bathroom and called 911. Sometime afterward, she walked out of the bathroom, and shot her ex’s girlfriend, 24-year-old Lisa Williams multiple times, police said. Williams later died at a hospital. Police say the two children were present the whole time, and witnessed the shooting.

“Our hearts and prayers go out to those that were impacted directly by this incident.” Bird said.

Administrators at Alpine School District also learned Monday that Cook was already facing two misdemeanor charges for domestic violence in the presence of children. Bird said when school employees are arrested their records go into a state database, that then goes back to the school district they work for. For some reason, that did not happen.

Cook was arraigned on the domestic violence charges in Herriman city court two weeks ago, and pleaded not guilty at that time. She is currently being held on suspicion of aggravated murder.

Bird said Cook was a health instructor at Lehi High School for over a year, before transferring to the newly-opened Skyridge High School in 2016.