They could also stop civil asset forfeiture - in 2014 that surpassed burglary in the US as the top form of theft by value. Without being charged or convicted of any crime police can take cash and property, which can then be sold for funding. The case is brought against the property instead of the individual, and then to get it back they have to prove the innocence that it wasn't used in a crime, rather than the state having to prove that it was.
Somehow they still manage to write people a lot of tickets, something that generates revenue for the police, and steal the money of legal marijuana businesses, something else that generates revenue for the police.
There are no consequences to the police for ignoring the parts of the job that do not directly generate revenue for the police.
This is not an overarching problem with "the criminal justice system" other than the fact that the police almost everywhere in the US have a culture of graft and rentseeking, and won't do anything if there isn't money or press involved.