I think you (understandably) misinterpreted "defund" the police to mean "disbanding" or "abolishing" the police.
It actually means redirecting police funds into more appropriate resources[1], such as first-responders trained to deal with mental-health issues. Police are often called for non-crimes. They also don't need millions for military-grade equipment...
1. https://www.chicagotribune.com/news/criminal-justice/ct-poli...