If this topic interests you, worth pointing out some similar projects, such as the Citizens Police Data Project of Chicago, which currently has 247K police complaints (and puts the code/data on Github) [0]. Note that it's about complaints -- not about all use of force, as in the NJ database. It also covers a single agency -- the Chicago PD. Ostensibly, the Chicago PD has put in the work to create a centralized database, making it relatively straightforward to get the bulk data once the records request/lawsuit succeeds. It's a much different situation when trying to corral the records from multiple agencies, all of which have their own IT systems and practices.
VICE did a mass records request for shooting incidents (again, a subset of use of force) from the 50 largest police departments. It took them 9 months to collect the data [1]
[0] https://invisible.institute/police-data/
[1] https://news.vice.com/en_us/article/a3jjpa/nonfatal-police-s...