Milia 222 had a special police force due to its unique environment. That organization didn't have an official power in the universe and could apply its authority only on the seven asteroids. It also had limitations when it came to private areas owned by influential families or similar groups.
The authority of the police force came from the governments of the main species on Milia 222. The Orlats, the Nele, the Fuveall, the Bise, the Tors, and the humans managed that organization through intricate interplanetary regulations that made sure to respect everyone.
Of course, Milia 222's unique environment had opened the way for corruption and similar issues, but every government turned a blind eye to them. Everything was fine as long as it didn't involve big political problems that could affect the alliance among the species.