Cops, of themselves, do not reduce crime rates......they are also very rarely present during the commission of a crime. When cops are called, the crime has already happened, with a victim already established. The vast majority of times police are not called until well after the crime has already happened......they may be injured, call family members first (this is very prevalent), or in a state of shock.
The liberals calling for gun control live very different lives than the rest of us.....they often have armed bodyguards, live behind exclusive gated communities with armed security, or a mix of the two. Nevermind it is often THEIR constituency murdering each other on the streets in Democrat-dominated urban landscapes.