https://kansasreflector.com/2023/10/29/politicians-love-to-cite-crime-data-its-often-wrong/#:~:text=The%20FBI%20transitioned%20to%20a,accepted%20crime%20data%20through%20NIBRS.
I’m sure there are a lot of articles like this. Apparently, the FBI changed to a new reporting system in 2021 and a lot of major cities no longer report everything.
Not a drop in crime...just a drop in crime statistics.
There was also a change around 2015, where many, many more crimes were reported by some districts who used the new system, while others used the old system, so everything was very apples-to-oranges.