Look, I agree with this approach pre high school, but it will not stop school shootings, even though it will probably help some kids find more friends. But the purpose of school is not to teach social values, no matter how much some people preach this.
The schools need to concentrate on the outline of learning that a class is following. Maybe a class on ethics could teach values. Because that would be the subject of the class, but a class on algebra has no business finding out who is lonely in class.
Note that the teacher could ask the class about which lessons they understood and which should be taught over, that might prove illustrating to the teacher.
Values are learned in RELATIONSHIP, CONNECTION individual to individual.
And by 6 years old, most of the values are already well on the way to being deep seated.
HOWEVER, a LOT of research has indicated that for kids who come from horrible backgrounds, ONE teacher showing some kindness and interest totally changed that child's destiny from horror and prison to sometimes great success.
More shockingly, sometimes it was ONE teacher showing one bit of kindness one day in the whole year that did the trick. Let that sink in.