The King case is very disturbing.
In Missouri v. McNeely, the Supreme Court recently ended forced blood draws in DUI matters unless the charge is a felony and there is a warrant. This new opinion, however, goes farther than a blood draw.
In McNeely, the evidence related to the charged crime. In King, the evidence was an attempt to find evidence in connection with other, unrelated cases where the law enforcement agency had no reason to believe that the connection existed. This should be the definition of an unreasonable search and seizure.
Even Justice Scalia would not go as far as the majority in King. A sensible decision would have been to set a standard similar to McNeely, requiring a warrant to identify at least a de minimis connection between the evidence sought and the investigation of the unsolved crime.