Criminals already do roam free. When a murderer, rapist, terrorist, or pedophile is a police officer or part of the ruling class, they usually get away with it. And it happens a lot.
All you did was mention that criminals exist. You provided zero evidence whatsoever that the police stop those criminals.
Police solve about 2% of crimes committed.
https://theconversation.com/police-solve-just-2-of-all-major-crimes-143878