I've read crime fiction all my life. A thing that's bothered me about crime fiction is that it's generally about one or two people, but there's not much about society. I want to get away from that particular pattern: a lead, a supporting role and backdrop characters.
In real life, people are integrated into society. That's what happens in my books as well. Minor characters don't just walk in and spout lines, they interact and have an effect on the events. It's not an isolated universe.