Update, 2/5 1:45PM Pacific: Title amended to address m4570d0n‘s pedantic comment.
Update, 2/6, 10:30AM Pacific: Reader joe argues per capita figures would be more intuitively accessible. Here is the relevant graph.
Figure 2: 12 month moving average of mass shooting casualties per million; deaths (dark red), wounded (pink). Source: Mother Jones, GunViolenceArchive.org. for January 2016, and author’s calculations.
Note: Mother Jones used a 4 death threshold for definition of mass shooting; I have used that criterion for tabulating January 2016 numbers.