There are have been about 600-650,000 sworn law officers employed in the United States any year between 2005 and 2016 (numbers vary depending on source). Sources: 1. https://www.bjs.gov/content/pub/pdf/nsleed.pdf 2. https://www.bjs.gov/content/pub/pdf/lpd16p_sum.pdf 3. https://ucr.fbi.gov/crime-in-the-u.s/2015/crime-in-the-u.s.-2015/tables/table-74

Of that number, about 10,000 individual officers have been arrested for a variety of crimes. Source: https://policecrime.bgsu.edu/Home/Crimes#  Methodolgy: https://policecrime.bgsu.edu/Home/Methods 

Here are the numbers for various criminal offenses charged to these officers: Agrivated assault- 1,100. Simple assault- 1,900. Domestic violence- 1,600. Forcible rape- 500. Source: https://policecrime.bgsu.edu/Home/Crimes# 

These arrests, I would guess, happened while the officers were off duty. I’ve never heard of an officer being arrested while on the job. Let’s look at complaints filed against on duty officers each year. This is more difficult bc this data can be hard to get from local agencies.

In 2002, there were 26,000 citizen complaints filed against officers for use of force alone. https://www.bjs.gov/content/pub/pdf/ccpuf.pdf

Of those complaints filed in 2002, 25% were found to be completely fabricated and another 34% had insufficient evidence to prove or disprove, which leaves us with at least ~11,000 complaints that definitely happened (conservatively).