Well some people don't want to go to school drop out or dont drop out, and do other things like steal. Get money for something you stole it feels like found money. It can become addictive like a drug.

Remember in Goodfellas Jimmy Burke just loved to steal he thought it was fun that is an associate without a gang in the beginning. I guess he had no friends to steal withbasva kid. So he recruit some local kids to steal with him.

That also happened in the Departed. Nickolson recruited poor kids in the neighbor to steal for him and with him.

That is what happens every where.

You can steal by yourself. You can steal with a friend. You can steal with a group of friends. Some people call that a gang or a crew.

Some people don't want to follow others in gang. But if they ever come up with a good way to get money. But they need help to pull it off. That is when they join a gang. If it works and they are making money they can be led. When that happens who ever led the gang before will either become a follower or he will disappear.

That is one of the reasons thieves can become killers.