Are there any studies that show beyond a certain level of policing there are further benefits to crime rate? It seems to me we keep arming the cops with ever mo

Are there any studies that show beyond a certain level of policing there are further benefits to crime rate? It seems to me we keep arming the cops with ever more expensive military equipment and generous pensions, and I doubt it translates to any impact on the crime rate. Though if you have studies showing otherwise I would happily change my mind!