its political theatre. the op is right. law enforcement can't go on unwarranted fishing expeditions. and they don't usually. the only time they ever do this is when there is a politician involved and the entire legal system is in on it.  > but why? because when things are political in nature there are two sides and they need to create a show to distract them from killing each other. both sides are out for blood and the best way to do that is to create a long drawn on legal process and play both sides off each other. eventually the politicals "cool off" and people move on. the process takes years. and usually the end result is a big nothing burger or there is an appeal and all charges are dropped.
United States