The data set includes 8,006 arrest incidents resulting in 13,623 charges involving 6,596 police officers from 2005 through 2012, with more years of data to come. Nearly half these incidents, Stinson and his research team concluded, were violent.
The data covers 2,830 state, local, and special law enforcement agencies across all 50 states plus Washington, D.C. That’s just a fraction of the approximately 18,000 law enforcement agencies and 1.1 million sworn officers in the U.S., so the data set is not comprehensive, but it’s the most extensive and ambitious look at cop crime to date.
So out of the 1.1 million sworn officers in the US, from 2005-2012 6596 of these were bad cops (who were caught). In terms of percentage, that's roughly 0.6% of the entire US police force.