The law is not being kept secret. The facts supporting the issuance of the warrant and the circumstances of its execution are. That is the causal definition o

The law is not being kept secret. The facts supporting the issuance of the warrant and the circumstances of its execution are. That is the causal definition of "where the evidence came from". That in and of itself is evidence. "I first heard about the defendant's shenanigans when I was attending my support group for compulsive liars, from Joe, the defendant's bitter ex-husband. As I recall he was covered in blood at the time." That is a factual circumstance related to the issuance of the warrant that would be relevant to the case, not just the issuance of the warrant itself. This is not a difficult distinction, it's one you're trying for whatever reason to ignore.