There are two characters written on the orange jackets (?) they are wearing. It seems like it says "北看" but I can't seem to find anything related to that meaning. If it's not "看", I hope someone can tell me what it is, and why is it even there on the jacket. They are in court, by the way.
This is short for "北x市xx看守所". The TV play is based on the city of Beihai(北海市) which belongs to Guangxi province(广西省), so 北 means 北海, 看 means 看守所. The typical name should be 北海市看守所. Actually, 北海 has at least two 看守所s. One is 北海第一看守所, the other is 北海第二看守所. If 北看 means 北海市第一看守所, then the other one should be short as 北二看.