It shows only a cumulative rise, from the first month to month 16. What was lethal use of force for police in the 16 months prior? How does it compare to historical highs and historical lows? What about adjusting for population growth?
All it is is a bunch of dots that accumulate. You could do the same for anything and make it look scary — suicide, car wrecks, death by power tools — but without context, and a point of comparison, it is meaningless.