A federal judge is expected to rule on whether an alleged drug cartel leader is being treated properly in a Chicago jail. Jesus Vicente Zambada Niebla is the son of one of Mexico’s notorious drug lords, and he’s charged with conspiring to bring drugs into the U.S.

He awaits his trial in Chicago’s Metropolitan Correctional Center downtown. Zambada Niebla’s attorneys filed a complaint claiming he has been held in isolation for 18 months and has no access to fresh air or sunlight. Attorneys think he should be allowed at least five hours of outdoor exercise a week and to be treated equally to other detainees.

But prosecutors say Zambada Niebla’s rights have not been violated and that allowing him outdoor exercise would put him at “risk of retribution by rival cartels.”

A judge is expected to make a decision later Wednesday.