D. Brian Burghart of the Reno News & Review has compiling a national database of deadly police violence. He believes that the lack of data is a deliberate policy:
The biggest thing I've taken away from this project is something I'll never be able to prove, but I'm convinced to my core: The lack of such a database is intentional. No government—not the federal government, and not the thousands of municipalities that give their police forces license to use deadly force—wants you to know how many people it kills and why.
It's the only conclusion that can be drawn from the evidence. What evidence? In attempting to collect this information, I was lied to and delayed by the FBI, even when I was only trying to find out the addresses of police departments to make public records requests. The government collects millions of bits of data annually about law enforcement in its Uniform Crime Report, but it doesn't collect information about the most consequential act a law enforcer can do.