The justice system wasn't really fair. Security tapes were not even checked. There were no trials. If a guard saw you commit a crime, you were taken and imprisoned. If you were suspected of committing a crime, you were taken and imprisoned. If someone succesfully framed you, you were taken and imprisoned. Although there had to be at least some evidence- even the tiniest bit of it and you could still get imprisoned. And once you were in there, you could not get out. Sucks, doesn't it?
They did not torture the prisoners, though. Jail wasn't actually too terrible except for the fact that they killed you after your 25th birthday.
Anyone who was 15-24 years old was immediately snatched and thrown into a cell on the prison wing of the ship. Anyone 14 and under was detained.
And for those who were 25 and over caught committing a crime? Immediate death penalty.
For years, Advivo's juvenile delinquents and prisoners were killed the day after their 25th birthdays to make more space for future convicts in the cells, as well as more room on the ship for future generations. They had no choice unless they could prove themselves worthy to remain.
So killing them after 25 was always how it went. Until now.
Advivo's leaders claim that they've given these groups of juveniles a "chance". Instead of being killed, they were sent down to Earth. If they prove that it's livable again, Advivo will descend and everyone is finally home- not to mention their crimes will be forgotten. If they don't prove that it's livable again- well, they die on Earth.