In my own opinion, the best way to reduce the crime level is stiffer penalties. However, this entails the building of more prisons, using tax dollars to build, staff and maintain. Few taxpayers are willing to vote this into effect when asked directly. It becomes a catch-22. They say they want less crime and stiffer penalties, but they don't want to pay for it. They don't seem to mind the fact that convicted felons are released from prison...until one moves next door or across the street from their own house. Then they mind it a lot.
But to answer your question, that is where the answer lies in my opinion. When people see the penalties for certain actions, and see that they are enforced, more people choose not to risk it. There will always be those who will risk it. Heck, there is a certain percentage of people who prefer to be incarcerated over having to make their own way in life.
And I know what you are about to say. That the reluctance of the population to approve the funds to enact these penalties is silent complicity with the crime rate. To a small extent it may be. But it's like saying that a teacher who fails to report suspected sexual abuse of a kindergarten student is a pedophile.