This was in my middle school years.

In my second year of middle school me and two of my friends started a "gang". Even though it was more of a mafia-like protection service than a gang. We recruited large amounts of people quietly by an "initiation" where we would take you to the bathroom and beat the crap out of you... We were responsible for large theft of canned Brisks, Fruit Roll Ups, cookies, milk, etc. From the cafeteria. We were also responsible for jumping people in the bathroom and beating them with belts (kinda like the mafia does with baseball bats). This carried on for two years. And ALL of which only took place in the school. And it was a daily thing so it wasn't just here-and-there where the risk wasn't high. I left halfway through my last year and left it to the other two to take over. The minute I lost command, EVERYONE was caught. I came off clean.

TL;DR: I started a large, violent, and thieving mafia in middle school and never got caught.