If you gather other evidence, it's called "parallel construction" and it's A Thing. It doesn't just apply to wire-taps; all sorts of evidence would be inadmissi

If you gather other evidence, it's called "parallel construction" and it's A Thing. It doesn't just apply to wire-taps; all sorts of evidence would be inadmissible, but of course once investigators know something there are often other ways of figuring out a means to get evidence (or, at least, getting to the point you can justify a warrant).