Rather than using the example of evidence that used to exist but no longer exists, I think a better preexisting example is evidence that has been deliberately h

Rather than using the example of evidence that used to exist but no longer exists, I think a better preexisting example is evidence that has been deliberately hidden. After all, encryption is just a method of hiding data from everyone that does not know the key. If law enforcement knows that the plans for the bank heist exist they still might not know that those plans are currently located in the suspects ex-boyfriends garage. The garage is not warrant proof, the police just don't know where to apply the warrant. The exact same thing is true in the case of encrypted data. Law enforcement needs the key to apply the warrant.