During the investigation of criminal cases, criminal suspects and their families are not allowed to meet, and the only person who can meet is the entrusted lawyer.
Criminal detention is 37 days at most. If it exceeds 37 days, it will generally turn into arrest. If the arrest is not approved, it will be transferred to bail pending trial or residential surveillance.
You don't have to worry about what will happen after 37 days, because if the police don't let people go, there must be legal procedures. If they don't let people go without formalities, the case handler will commit a crime, and his direct leader will also bear the responsibility, so no one will be stupid enough to refuse to handle it when it expires, so you can hardly worry about not letting people go for 37 days without formalities. All you have to do is wait 37 days, and then ask the person handling this case for the result.