Keep in mind when looking at data like this that we do not actually know how many people police kill. Despite the 1994 crime bill mandating the detailed reporting of every police killing to the feds no one has ever forced them to do it. What we are seeing are only the ones that ended up having an outside entity involved in the investigation (be it of the crime leading to the killing or of the killing it's self).
Years ago, in an interview with a an industry rag Patrick Hendry, head of the NY police union, the largest of it's kind, was asked about this and he answered that "most" killings never leave the department that employed the officer(s) who committed the homicide.
It total, since 2013, MPV has recorded 12,318 police killings in the US,over 5,000 more deaths than all US military personnel killed in Afghanistan, Iraq, Syria, Yemen and other “war on terror” battlefields from October 2001 through October 2019, according to the Watson Institute at Brown University.
1,200 people is nothing compared to what would happen during a civil war. It is multiple orders of magnitude shy of what even a few months of civil war would cause.
As an example, all US cities are within 48 hours of being in starvation all the time. 24-48 hours before all store shelves are empty is generally the accepted logistics.