Here is the Los Angeles benevolent association https://larfpa.org/benevolent-association/
Donations to these organizations are not usually tax deductible. Giving them a relatively small amount of money, say $10,000 per year, goes a very long way to making you friendly with them and the chief of police / sheriff / etc.
These organizations are basically slush funds. The money is used to throw parties at best, or enrich retired and connected police at worst. The state police have one as well, and they are supra-entities across the state. Donating to these organizations is one way Jeffrey Epstein was able to avoid prison for the sexual assault charges in Palm Beach.
If you are a wealthy person that likes to party, do hard drugs, or throw your own events, I highly recommend engendering yourselves with the local and state police via money donations. It goes a long way to solving problems.
My father (RIP) was a musician who played at many police events in the city I grew up. Police are people, and generally average intelligence people. They are no better or worse than other people, except they have the benefit of being above the law in all cases except those that rise to the level of a public relations disaster. My father was an alcoholic who should have had multiple DUIs, but always got out of it thanks to his local connections, among other legal issues he should have had. He was not a good person.
I am not posting this as an advocacy good or bad, I am posting this as advice for the reality we live