Police notebook: Bloomington chief reports violent crime down by 24.3% at State of City

More than three weeks ago, at Bloomington’s State of the City event, Bloomington police chief Mike Diekhoff reported a 24.3% drop in violent crime over the last year.

On its face, that percentage drop doesn’t look consistent with the numbers reported to the board of public safety earlier this year—because none of the individual types of crime show more than a single digit percentage drop from 2023 to 2024.

But it turns out that’s because in the numbers reported to the board of public safety, the category of “assault” reflected the sum of two kinds of assault—aggravated assault and simple assault. The “violent crime” statistic that Diekhoff reported includes just aggravated assault. The other three types of violent crime under the FBI’s definition of “violent crime” are homicide, rape, and robbery.

The difference between simple assault and aggravated assault is that aggravated assault often involves a weapon or an intent to inflict serious harm, whereas simple assault doesn’t generally involve a weapon or serious injury.

The violent crime totals in 2023 and 2024 for Bloomington are 259 and 196 respectively, which works out to the 24.3% drop [=(259-196)/259] that Diekhoff reported.

2023
Murder: 2
Rape: 30
Robbery: 49
Aggravated Assault: 178
Total: 259

2024
Murder: 3
Rape: 32
Robbery: 46
Aggravated Assault: 115
Total: 196

As the biggest category of violent crime, the aggravated assault numbers drive the trend for violent crimes overall. The other three types of violent crime were the same in both years (81), so the 35% drop in aggravated assault, from 178 to 115, explains the 24.3% drop in violent crime overall.

Based on the FBI crime data for Bloomington, the drop in aggravated assault from 2023 to 2024 is part of a downward trend that started in 2022. That’s after an upward trend that started in 2014 and peaked over the years from 2019 to 2021, when Bloomington saw more than 350 aggravated assaults in each of those years.

For the two overlapping years of data from the FBI, there’s a mismatch between the numbers from Bloomington Police Department and the FBI, which gets its figures from BPD. Diekhoff told The B Square that his data analyst reported the numbers to the FBI the same as to The B Square—they’ve now asked the FBI why they aren’t the same.

There’s another curious output from the FBI’s website numbers. For the Monroe County sheriff’s department data, there are –4 rapes recorded for 2019. How is a negative number possible in any crime category? Responding to a B Square question submitted to the FBI, the email account for Uniform Crime Statistics replied that the most likely reason is that the offender was charged in a month before the month showing the negative number, but then the charge was dropped.

About the specific number for Monroe County in 2019, the FBI stated: “The month showing the negative number (in this case, January 2019), more than likely, the person or persons being charged with these Rapes were no longer being charged as of January 2019, causing the negative number. This is most common with Rape and Murder.”