Why not allow any parent to reunite with children by simply going to detention center and asking?

Ranchmom1

Notice that I said "parent" in my question. Certainly whoever that showed upo asking for their children would have to provide undisputable proof that they are the parent(s). The parent(s) would then be allowed to take the children and either be deported or remain in the US , whichever our laws require. But in either case, the parents get the children.