This is why police need better training and better screening during the hiring process.
Given your comment, you've already formed an opinion:
these two specific Cops were not adequately trained nor screened.
I wasn't able to ascertain ANY root causes that explain why they did what they did. You obviously have some insight or information that wasn't part of the video or narrative.
What are the Cops taught now? Specifically the Cops working the jurisdiction in this story? How was their training lacking? Can you give specifics?
Based on your answer to the above, what changes do you think ought to be made to their curriculum?
Do the same for screening -- details on how it's done now, and what you recommend for future screening processes. Was there something in these Cops' background the process missed? Did they have a history of violence, domestic abuse, etc. that went unnoticed or which was dismissed as unimportant?
I'd be interested to know what your recommendations are. "Better" is kind of ambiguous and relative.
I only ask, because I find it inconceivable that anyone would do what they did merely because they missed a day at the academy when the instructors went over
The Use Of Force Continuum. Neither do I think any specific "screening" would have predicted how these two would act in this situation.