It is no secret Pine Bluff has a protracted crime problem — at least that is a common perception. Part of this view is driven by the stratospheric rate of local murders relative to the rest of the country. Some is due to the Pine Bluff Police Department’s failure to properly manage its own image. In response, the local police administration has become increasingly withdrawn and hesitant to provide adequate information to the media. While all these issues are separable, more often than not, they combine to form a story that no one wants to hear. As with many civic ills, we are not alone in this struggle of image and numbers.
The Milwaukee Sentinel newspaper just published a lengthy investigative report alleging that the Milwaukee Police Department had systematically suppressed violent crime numbers. Writing for the paper, Ben Poston reported that more than 500 violent incidents from 2009 to 2011 had been incorrectly categorized as minor assaults. The errors might mean the city had a slight increase in violent crime in 2011, instead of the 2.3 percent decline touted by Police Chief Edward Flynn in February.
In response, the MPD chose to more actively shape its media image by publishing its own news service called, The Source. The MPD has also taken the proverbial bull by the horns with a more tailored social media presence.
While these developments signal a willingness to engage the public, the MPD has yet to effectively deal with the larger elephant in the room: the statistics. This dimension of their problem bears directly on our local concerns.
As recently reported in the Commercial, the Pine Bluff Police Department released figures reflecting a slight decrease in crimes against persons versus the same period last year. Moreover, the department asserts that crime has declined over the last five months. While this is all well and good, such simplistic reports betray the complexity of crime statistics.
Independent reporting for Pine Bluff & Jefferson County since 1879.
First, comparisons of raw numbers of criminal incidents, while seemingly useful, impart little information toward a meaningful grasp of the true picture of local crime. Take for example a town that has 100 robberies per month. In the next county over, another community also has 100 robberies per month. In one view, 100 equals 100… therefore the towns have similar pictures of crime. This is true only if they have similar populations. If town number one has twice the population of town number two (but the same number of robberies), then town number two has twice the robbery rate — the citizens in town two have a much higher probability of being victims of robberies. Therefore, the only meaningful comparisons can be expressed in terms of rates, not raw numbers — as the local police department is almost exclusively wont to do.
Second, there’s the matter of a thing called “statistical significance.” In other words, if the crime numbers dropped over a certain period, is the drop due to a discernable change in crime fighting strategy, or is it merely an artifact of chance — would it have happened anyway if the police did nothing differently? Unless the amount of change is large enough to refute the mathematical probability that random chance is possibly at issue, then the move up or down doesn’t tell us much about crime in the city. One way this works is by comparing local rates of change to national levels — if local levels are very close to national levels, then it is likely that nothing done locally caused much change. Of course, that’s not how politicians and police officials will portray it.
For instance, we know that our 2012 murder rate is currently 4.5 times the national average. That’s sufficiently different from national levels that we can say confidently that something has gone wrong. We would also like to believe that local crime of other kinds is on its way down. Unfortunately, the simplistic statistics provided by the Pine Bluff Police Department don’t afford us that opportunity.