A childhood belief about criminals

I thought that there had to be a "criminal store" where one could buy burglar masks and those striped sweaters burglars were portrayed as wearing, guns, glass cutters, etc. I asked my dad where criminals got their guns. He said, "on the steet". I knew that meant OUR street, so I was looking out for handguns scattered in the gutter. He also explaned on said street is where they have to buy silencers for the guns too - because silencers are illegal. This was doubly confusing becasue shooting people in general seemed illegal.