Not going to happen.  

Even London, which has the most invasive and pervasive CCTV system in the world, can't cover all the crimes committed there.  

There is not enough money to do what you want to do, either.  

If its a choice between more police and police cameras, cameras are going to be second place or below.

Cameras don't arrest people committing crimes; police officers do.  

The friends of those arrested believe their friends; the jury and Judges are supposed to be impartial.  Friends aren't.