Part of the problem is that we underfund and understaff the courts so that there is little chance of a speedy trial unless one cops a plea deal.
There's an insane backlog at the Bronx criminal court. It's pretty insane because they aren't saving any money by keeping someone at Rikers for 3 years pending a trial.
Unfortunately, we live in a world of budget cuts. Nobody really cares when the cuts hurt poor back people. So, in New York the thinking is that you make sure the pain is felt among these poor black communities and not on the more politically powerful white voters.