You’ve probably heard this by now: The decision by Ferguson’s grand jury wasn’t unique. Cops are rarely indicted.

And it’s an understatement to say that the data on how many people police kill a year is a bit questionable. For example, the federal statistic that there have been roughly 400 “justifiable police homicides” a year over the last half dozen years is shaky to say the least. Those killed unjustifiably are “skirted,” according to analysis by Nate Silver’s FiveThirtyEight.com. But perhaps we can dive into a broader question: How often do police go to jail for misconduct?

To answer that, we turned to a study by the CATO Institute’s National Police Misconduct Reporting Project. They tracked 8,300 credible reports alleging police misconduct in the U.S. between April 2009-Dec. 2010, the most recent study CATO has conducted.

This figures suggest that a little over a third of convicted cops see any jail time.

Police convictions and incarcerations much lower than general public

Just over a third of cops convicted of a criminal charge went to jail or prison. But digging into data released by the U.S. Department of Justice, CATO researchers found that on average, 70 percent of convicted non-police officers — the so-called “general population” of Americans — go behind bars, a difference of 33 percentage points.

When cops do go to jail, they also go for shorter periods of time than other convicts: An average of 34.6 months for police officers, compared to an average 49 months for everyone else.

This would appear to indicate that there are disparities on a national scale between how law enforcement officers are treated in the criminal justice system since conviction and incarceration rates for law enforcement officers are nearly half that of the conviction and incarceration rates for the general public and, even when convicted, law enforcement officers spend 29% less time behind bars on average than the rest of the public. — David Packman, CATO